Becoming Catholic #18: What Did the Ancient Church Believe? The Unity and Necessity of the Church for Salvation

Making Wisdom Popular

The “Becoming Catholic” blog series is a multi-part, multi-year, bite-size, fact-focused attempt at describing the journey of a lifelong protestant to the Catholic Church.  You can read all the individual articles here.

This will be the first post I include on Substack, in addition to my personal website.

Based on the many questions I’ve received from so many about what the Church Fathers believed, and how that led to my conversion, I’ve decided to do another mini-series within my Becoming Catholic series called What Did the Ancient Church Believe? The goal is to provide a bird’s-eye-view of what the ancient Church believed. I will choose a topic, and then provide a wide collection of Church Father quotes I discovered in my own research.

The first topic I’ll cover is what the Church Fathers said about the unity and necessity of the Church for salvation. This is barely scratching the surface, and I plan to add to each of these posts as I collect and archive more and more quotes. But these are a broad sampling of the quotes I found in my own research that led me to the Catholic Church. I discovered that from the very beginning, the Church Fathers throughout the Christian world, East and West, in every century, asserted and defended that Christ founded only one, united Church, holding the same Faith, and under the same government of bishops, which they all called the Catholic [“Universal”] Church, whose communion every Christian was obligated to keep, and outside of which there was no salvation.

Here is a broad sampling of what I found, beginning with my confirmation Saint, St. Ignatius of Antioch, who knew the Apostle John, and wrote only about seven decades after the ascension of Christ.

ST. IGNATIUS OF ANTIOCH (died c. AD 107)

St. Ignatius of Antioch, Epistle to the Philadelphians (§§3-4):

(§3) …Do not err, my brethren. If any man follows him that makes a schism in the Church, he shall not inherit the kingdom of God. If anyone walks according to a strange opinion, he agrees not with the passion [of Christ].

(§4) Take heed, then, to have but one Eucharist. For there is one flesh of our Lord Jesus Christ, and one cup to [show forth] the unity of His blood; one altar; as there is one bishop, along with the presbytery and deacons, my fellow-servants: that so, whatsoever you do, you may do it according to [the will of] God.

St. Ignatius of Antioch, Epistle to the Smyrnaeans (§8):

(§8) See that you all follow the bishop, even as Jesus Christ does the Father, and the presbytery as you would the apostles; and reverence the deacons, as being the institution of God. Let no man do anything connected with the Church without the bishop. Let that be deemed a proper Eucharist, which is [administered] either by the bishop, or by one to whom he has entrusted it. Wherever the bishop shall appear, there let the multitude [of the people] also be; even as, wherever Jesus Christ is, there is the Catholic Church. It is not lawful without the bishop either to baptize or to celebrate a love-feast; but whatsoever he shall approve of, that is also pleasing to God, so that everything that is done may be secure and valid.

St. Ignatius of Antioch, Epistle to the Trallians (§§2-3, 6-7)

(§2) For, since you are subject to the bishop as to Jesus Christ, you appear to me to live not after the manner of men, but according to Jesus Christ, who died for us, in order, by believing in His death, you may escape from death. It is therefore necessary that, as you indeed do, so without the bishop you should do nothing, but should also be subject to the presbytery, as to the apostle of Jesus Christ, who is our hope, in whom, if we live, we shall [at last] be found…

(§3) In like manner, let all reverence the deacons as an appointment of Jesus Christ, and the bishop as Jesus Christ, who is the Son of the Father, and the presbyters as the Sanhedrin of God, and assembly of the apostles. Apart from these, there is no Church…

(§6) I therefore, yet not I, but the love of Jesus Christ, entreat you that you use Christian nourishment only, and abstain from herbage of a different kind; I mean heresy. For those [that are given to this] mix up Jesus Christ with their own poison, speaking things which are unworthy of credit, like those who administer a deadly drug in sweet wine, which he who is ignorant of does greedily take, with a fatal pleasure leading to his own death.

(§7) Be on your guard, therefore, against such persons. And this will be the case with you if you are not puffed up, and continue in intimate union with Jesus Christ our God, and the bishop, and the enactments of the apostles. He that is within the altar is pure, but he that is without is not pure; that is, he who does anything apart from the bishop, and presbytery, and deacons, such a man is not pure in his conscience.

ST. IRENAEUS OF LYON (c. 130-c. 202)

St. Irenaeus of Lyon, Against Heresies (Book Three, Ch. 24, §1):

(§1) …“For in the Church,” it is said, “God has set apostles, prophets, teachers,” [1 Cor. 12:28] and all the other means through which the Spirit works; of which all those are not partakers who do not join themselves to the Church, but defraud themselves of life through their perverse opinions and infamous behavior. For where the Church is, there is the Spirit of God; and where the Spirit of God is, there is the Church, and every kind of grace; but the Spirit is truth. Those, therefore, who do not partake of Him, are neither nourished into life from the mother’s breasts, nor do they enjoy that most limpid fountain which issues from the body of Christ; but they dig for themselves broken cisterns [Jer. 2:13] out of earthly trenches, and drink putrid water out of the mire, fleeing from the faith of the Church lest they be convicted; and rejecting the Spirit, that they may not be instructed.

St. Irenaeus of Lyon, Against Heresies (Book Four, Ch. 33, §§7-8):

(§7) He [the spiritual man] shall also judge those who give rise to schisms, who are destitute of the love of God, and who look to their own special advantage rather than to the unity of the Church; and who for trifling reasons, or any kind of reason which occurs to them, cut in pieces and divide the great and glorious body of Christ, and so far as in them lies, [positively] destroy it — men who prate of peace while they give rise to war, and do in truth strain out a gnat, but swallow a camel. Matthew 23:24 For no reformation of so great importance can be effected by them, as will compensate for the mischief arising from their schism. He shall also judge all those who are beyond the pale of the truth, that is, who are outside the Church; but he himself shall be judged by no one…

(§8) True knowledge is [that which consists in] the doctrine of the apostles, and the ancient constitution of the Church throughout all the world, and the distinctive manifestation of the body of Christ according to the successions of the bishops, by which they have handed down that Church which exists in every place [i.e. the Catholic Church], and has come even unto us, being guarded and preserved without any forging of Scriptures, by a very complete system of doctrine, and neither receiving addition nor [suffering] curtailment [in the truths which she believes]; and [it consists in] reading [the word of God] without falsification, and a lawful and diligent exposition in harmony with the Scriptures, both without danger and without blasphemy; and [above all, it consists in] the pre-eminent gift of love [1 Cor. 13; 2 Cor. 8:1] which is more precious than knowledge, more glorious than prophecy, and which excels all the other gifts [of God].

TERTULLIAN (c. 155-c. 220)

Tertullian, Prescription Against Heretics (§4):

(§4) …Who also are the Antichrists, both now and evermore, but the men who rebel against Christ? Heresies, at the present time, will no less rend the church by their perversion of doctrine, than will Antichrist persecute her at that day by the cruelty of his attacks, except that persecution make seven martyrs, (but) heresy only apostates. And therefore “heresies must needs be in order that they which are approved might be made manifest,” [1 Cor. 11:19] both those who remained steadfast under persecution, and those who did not wander out of their way into heresy…

(§30) Where was Marcion then [when the Apostles passed tradition on to their successors], that shipmaster of Pontus, the zealous student of Stoicism? Where was Valentinus then, the disciple of Platonism? For it is evident that those men lived not so long ago—in the reign of Antoninus for the most part—and that they at first were believers in the doctrine of the Catholic Church, in the church of Rome under the episcopate of the blessed Eleutherus, until on account of their ever-restless curiosity, with which they even infected the brethren, they were more than once expelled…

ORIGEN (c. 184-c. 253)

Origen, Homily 3 on Joshua (§5)[1]:

(§5) …Therefore, if anyone wants to be saved, let him come into the house…let him come in order to be able to attain salvation. Let him come to this house in which the blood of Christ is the sign of redemption…

Let no one persuade himself, let no one deceive himself. Outside this house, that is, outside the Church, no one is saved. If anyone goes outside, he is responsible for his own death. This is the significance of the blood, for this is also the purification that is manifest through the blood.

ST. CYPRIAN OF CARTHAGE (c. 210-258)

St. Cyprian of Carthage, Epistle 61: To Pomponius, Concerning Some Virgins (§4):

(§4) …Nor let them think that the way of life or of salvation is still open to them, if they have refused to obey the bishops and priests, since in Deuteronomy the Lord God says, “And the man that will do presumptuously, and will not hearken unto the priest or judge, whosoever be shall be in those days, that man shall die, and all the people shall hear and fear, and do no more presumptuously.” [Deut. 17:12-13] God commanded those who did not obey His priests to be slain, and those who did not hearken to His judges who were appointed for the time. And then indeed they were slain with the sword, when the circumcision of the flesh was yet in force; but now that circumcision has begun to be of the spirit among God’s faithful servants, the proud and contumacious are slain with the sword of the Spirit, in that they are cast out of the Church. For they cannot live out of it, since the house of God is one, and there can be no salvation to any except in the Church.

St. Cyprian of Carthage, Epistle 68: To Florentius Pupianus (§8):

(§8) And the Lord also in the Gospel, when disciples forsook Him as He spoke, turning to the twelve, said, “Will you also go away?” then Peter answered Him, “Lord, to whom shall we go? You have the word of eternal life; and we believe, and are sure, that You are the Son of the living God.” [John 6:67-69] Peter speaks there, on whom the Church was to be built, teaching and showing in the name of the Church, that although a rebellious and arrogant multitude of those who will not hear and obey may depart, yet the Church does not depart from Christ; and they are the Church who are a people united to the priest, and the flock which adheres to its pastor. Whence you ought to know that the bishop is in the Church, and the Church in the bishop; and if anyone be not with the bishop, that he is not in the Church, and that those flatter themselves in vain who creep in, not having peace with God’s priests, and think that they communicate secretly with some; while the Church, which is Catholic and one, is not cut nor divided, but is indeed connected and bound together by the cement of priests who cohere with one another.

St. Cyprian of Carthage, Epistle 69: To Januarius and Other Numidian Bishops (§§2-3):

(§2) …For when we say, “Do you believe in eternal life and remission of sins through the holy Church?” we mean that remission of sins is not granted except in the Church, and that among heretics, where there is no Church, sins cannot be put away…Further, it is the Eucharist whence the baptized are anointed with the oil sanctified on the altar. But he cannot sanctify the creature of oil, who has neither an altar nor a church; whence also there can be no spiritual anointing among heretics, since it is manifest that the oil cannot be sanctified, nor the Eucharist celebrated at all among them.

(§3) …Wherefore we who are with the Lord, and maintain the unity of the Lord, and according to His condescension administer His priesthood in the Church, ought to repudiate and reject and regard as profane whatever His adversaries and the antichrists do; and to those who, coming out of error and wickedness, acknowledge the true faith of the one Church, we should give the truth both of unity and faith, by means of all the sacraments of divine grace.

St. Cyprian of Carthage, Epistle 72: To Jubaianus (§§1-3, 7-8, 10-11, 13, 20-21, 24):

(§1) …You have written to me, dearest brother, wishing that the impression of my mind should be signified to you, as to what I think concerning the baptism of heretics; who, placed without, and established outside the Church, arrogate to themselves a matter neither within their right nor their power…[T]here is one baptism which is appointed in the Catholic Church…

(§2) …But we who hold the head and root of the one Church know, and trust for certain, that nothing is lawful there outside the Church…

(§3) But among us it is no new or sudden thing for us to judge that those are to be baptized who come to the Church from among the heretics…and thenceforward until the present day, so many thousands of heretics in our provinces have been converted to the Church…For it is not difficult for a teacher to insinuate true and lawful things into his mind, who, having condemned heretical pravity, and discovered the truth of the Church, comes for this purpose, that he may learn, and learns for the purpose that he may live. We ought not to increase the stolidity of heretics by the patronage of our consent, when they gladly and readily obey the truth…

(§7) But it is manifest where and by whom remission of sins can be given; to wit, that which is given in baptism. For first of all the Lord gave that power to Peter, upon whom He built the Church, and whence He appointed and showed the source of unity—the power, namely, that whatsoever he loosed on earth should be loosed in heaven.

And after the resurrection, also, He speaks to the apostles, saying, “‘As the Father has sent me, even so I send you.’ And when He had said this, He breathed on them, and says, unto them, ‘Receive the Holy Ghost: whosesoever sins you remit, they are remitted unto them; and whosesoever sins you retain, they are retained.’” [John 20:21-23] Whence we perceive that only they who are set over the Church and established in the Gospel law, and in the ordinance of the Lord, are allowed to baptize and to give remission of sins; but that without, nothing can either be bound or loosed, where there is none who can either bind or loose anything.

(§8) Nor do we propose this, dearest brother, without the authority of divine Scripture, when we say that all things are arranged by divine direction by a certain law and by special ordinance, and that none can usurp to himself, in opposition to the bishops and priests, anything which is not of his own right and power. For Korah, Dathan, and Abiram endeavored to usurp, in opposition to Moses and Aaron the priest, the power of sacrificing; and they did not do without punishment what they unlawfully dared. The sons of Aaron also, who placed strange fire upon the altar, were at once consumed in the sight of an angry Lord; which punishment remains to those who introduce strange water by a false baptism, that the divine vengeance may avenge and chastise when heretics do that in opposition to the Church, which the Church alone is allowed to do…

(§10) …[B]aptism…is only granted to the one and only Church. It is a good soldier’s duty to defend the camp of his general against rebels and enemies…Why do we receive as allowed an adulterous and alien church, a foe to the divine unity, when we know only one Christ and His one Church? The Church, setting forth the likeness of paradise, includes within her walls fruit-bearing trees, whereof that which does not bring forth good fruit is cut off and is cast into the fire. These trees she waters with four rivers, that is, with the four Gospels, wherewith, by a celestial inundation, she bestows the grace of saving baptism. Can anyone water from the Church's fountains who is not within the Church? Can one impart those wholesome and saving draughts of paradise to any one if he is perverted, and of himself condemned, and banished outside the fountains of paradise, and has dried up and failed with the dryness of an eternal thirst?

(§11) The Lord cries aloud, “that whosoever thirsts should come and drink of the rivers of living water that flowed out of His bosom.” Whither is he to come who thirsts? Shall he come to the heretics, where there is no fountain and river of living water at all; or to the Church which is one, and is founded upon one who has received the keys of it by the Lord’s voice? It is she who holds and possesses alone all the power of her spouse and Lord. In her we preside; for her honor and unity we fight; her grace, as well as her glory, we defend with faithful devotedness. We by the divine permission water the thirsting people of God; we guard the boundaries of the living fountains. If, therefore, we hold the right of our possession, if we acknowledge the sacrament of unity, wherefore are we esteemed prevaricators against truth? Wherefore are we judged betrayers of unity? The faithful, and saving, and holy water of the Church cannot be corrupted and adulterated, as the Church herself also is uncorrupted, and chaste, and modest. If heretics are devoted to the Church and established in the Church, they may use both her baptism and her other saving benefits. But if they are not in the Church, nay more, if they act against the Church, how can they baptize with the Church's baptism?…

(§13) …Nor let anyone say, We follow that which we have received from the apostles, when the apostles only delivered one Church, and one baptism, which is not ordained except in the same Church…

(§20) …Wherefore, dearest brother, we ought both firmly to maintain the faith and truth of the Catholic Church, and to teach, and by all the evangelical and apostolic precepts to set forth, the plan of the divine dispensation and unity.

(§21) …[N]ot even the baptism of a public confession and blood can profit a heretic to salvation, because there is no salvation out of the Church…

(§24) …[N]o remission of sins can be given outside the Church, they more eagerly and readily hasten to us, and implore the gifts and benefits of the Church our Mother, assured that they can in no wise attain to the true promise of divine grace unless they first come to the truth of the Church.

St. Cyprian of Carthage, Epistle 73: To Pompey (§11):

(§11) …Peter himself, showing and vindicating the unity, has commanded and warned us that we cannot be saved, except by the one only baptism of one Church. “In the ark,” says he, “of Noah, few, that is, eight souls, were saved by water, as also baptism shall in like manner save you.” [1 Pet. 3:20-21] In how short and spiritual a summary has he set forth the sacrament of unity! For as, in that baptism of the world in which its ancient iniquity was purged away, he who was not in the Ark of Noah could not be saved by water, so neither can he appear to be saved by baptism who has not been baptized in the Church which is established in the unity of the Lord according to the sacrament of the one ark.

St. Cyprian of Carthage, Treatise I: On the Unity of the Catholic Church (§6):

(§6) The spouse of Christ cannot be adulterous; she is uncorrupted and pure. She knows one home; she guards with chaste modesty the sanctity of one couch. She keeps us for God. She appoints the sons whom she has born for the kingdom. Whoever is separated from the Church and is joined to an adulteress, is separated from the promises of the Church; nor can he who forsakes the Church of Christ attain to the rewards of Christ. He is a stranger; he is profane; he is an enemy. He can no longer have God for his Father, who has not the Church for his mother. If anyone could escape who was outside the Ark of Noah, then he also may escape who shall be outside of the Church. The Lord warns, saying, “He who is not with me is against me, and he who gathers not with me scatters.” [Matt. 12:30] He who breaks the peace and the concord of Christ, does so in opposition to Christ; he who gathers elsewhere than in the Church, scatters the Church of Christ. The Lord says, “I and the Father are one” [John 10:30]; and again it is written of the Father, and of the Son, and of the Holy Spirit, “And these three are one.” [1 John 5:7] And does anyone believe that this unity which thus comes from the divine strength and coheres in celestial sacraments, can be divided in the Church, and can be separated by the parting asunder of opposing wills? He who does not hold this unity does not hold God’s law, does not hold the faith of the Father and the Son, does not hold life and salvation.

LACTANTIUS (c. 250-c. 325)

Lactantius, The Divine Institutes (Book Four, Ch. 30):

(Chapter 30) But since many heresies have existed, and the people of God have been rent into divisions at the instigation of demons, the truth must be briefly marked out by us, and placed in its own peculiar dwelling-place, that if any one shall desire to draw the water of life, he may not be borne to broken cisterns which hold no water, but may know the abundant fountain of God, watered by which he may enjoy perpetual light. Before all things, it is befitting that we should know both that He Himself and His ambassadors foretold that there must be numerous sects and heresies, which would break the unity of the sacred body; and that they admonished us to be on our guard with the greatest prudence, lest we should at any time fall into the snares and deceits of that adversary of ours, with whom God has willed that we should contend…There were some of our religion whose faith was less established, or who were less learned or less cautious, who rent the unity and divided the Church. But they whose faith was unsettled, when they pretended that they knew and worshipped God, aiming at the increase of their wealth and honor, aspired to the highest sacerdotal power; and when overcome by others more powerful, preferred to secede with their supporters, than to endure those set over them, over whom they themselves before desired to be set.

…But all of these, ensnared by frauds of demons, which they ought to have foreseen and guarded against, by their carelessness lost the name and worship of God. For when they are called Phrygians, or Novatians, or Valentinians, or Marcionites, or Anthropians, or Arians, or by any other name, they have ceased to be Christians, who have lost the name of Christ, and assumed human and external names. Therefore it is the Catholic Church alone which retains true worship.

This is the fountain of truth, this is the abode of the faith, this is the temple of God; into which if anyone shall not enter, or from which if any shall go out, he is estranged from the hope of life and eternal salvation. No one ought to flatter himself with persevering strife. For the contest is respecting life and salvation, which, unless it is carefully and diligently kept in view, will be lost and extinguished. But, however, because all the separate assemblies of heretics call themselves Christians in preference to others, and think that theirs is the Catholic Church, it must be known that the true Catholic Church is that in which there is confession and repentance, which treats in a wholesome manner the sins and wounds to which the weakness of the flesh is liable.

ST. CYRIL OF JERUSALEM (c. 313-386)

St. Cyril of Jerusalem, Catechetical Lecture 18 (§§22-23, 26, 28):

(§22) …Now then let me finish what still remains to be said for the Article [of the Creed], “In one Holy Catholic Church,” on which, though one might say many things, we will speak but briefly.

(§23) It is called Catholic then because it extends over all the world, from one end of the earth to the other; and because it teaches universally and completely one and all the doctrines which ought to come to men's knowledge, concerning things both visible and invisible, heavenly and earthly ; and because it brings into subjection to godliness the whole race of mankind, governors and governed, learned and unlearned; and because it universally treats and heals the whole class of sins, which are committed by soul or body, and possesses in itself every form of virtue which is named, both in deeds and words, and in every kind of spiritual gifts…

(§26) But since the word Ecclesia is applied to different things (as also it is written of the multitude in the theatre of the Ephesians, “And when he had thus spoken, he dismissed the Assembly” [Acts 19:14]), and since one might properly and truly say that there is a Church of evil doers, I mean the meetings of the heretics, the Marcionists and Manichees, and the rest, for this cause the Faith has securely delivered to you now the Article [of the Creed], “And in one Holy Catholic Church”; that you may avoid their wretched meetings, and ever abide with the Holy Church Catholic in which you were regenerated. And if ever you are sojourning in cities, inquire not simply where the Lord’s House is (for the other sects of the profane also attempt to call their own dens houses of the Lord), nor merely where the Church is, but where is the Catholic Church. For this is the peculiar name of this Holy Church, the mother of us all, which is the spouse of our Lord Jesus Christ, the Only-begotten Son of God (for it is written, “As Christ also loved the Church and gave Himself for it,” [Eph. 5:25] and all the rest) and is a figure and copy of Jerusalem which is above, which is free, and the mother of us all [Gal. 4:26]; which before was barren, but now has many children…

(§28) In this Holy Catholic Church receiving instruction and behaving ourselves virtuously, we shall attain the kingdom of heaven, and inherit eternal life; for which also we endure all toils, that we may be made partakers thereof from the Lord. For ours is no trifling aim, but our endeavor is for eternal life…

ST. JEROME (c. 342/347-420)

St. Jerome, Epistle 15: To Pope Damasus (§2):

My words are spoken to the successor of the fisherman, to the disciple of the cross. As I follow no leader save Christ, so I communicate with none but your blessedness, that is with the chair of Peter. For this, I know, is the rock on which the church is built! [Matt. 16:18] This is the house where alone the paschal lamb can be rightly eaten. [Ex. 12:22] This is the Ark of Noah, and he who is not found in it shall perish when the flood prevails.

St. Jerome, Commentary on Titus (3:10-11)[2]:

But heretics pass judgment on themselves, by withdrawing from the church by their own choice. This withdrawal seems to be the condemnation of private conscience. I think that the difference between heresy and schism is that heresy contains perverse doctrine, schism separates from the church on account of episcopal dissension. To be sure this can be understood this way to some extent in the beginning. However that may be, no schism fails to concoct some heresy for itself, so that it may appear to have withdrawn from the Church rightly.

ST. AUGUSTINE (354-430)

St. Augustine, Of True Religion (§§9-10, 12)[3]:

(§9) …So religion is to be sought neither in the confusion of the pagans, nor in the offscourings of the heretics, nor in the insipidity of schismatics, nor in the blindness of the Jews, but only among those who are called Catholic or orthodox Christians, that is, guardians of truth and followers of right.

(§10) This Catholic Church, strongly and widely spread throughout the world, makes use of all who err, to correct them if they are willing to be aroused, and to assist its own progress. It makes use of the nations as material for its operations, of heretics to try its own doctrine, of schismatics to prove its stability, of the Jews as a foil to its own beauty. Some it invites, others it excludes, some it leaves behind, others it leads. To all it gives power to participate in the grace of God, whether they are as yet to be formed or reformed, admitted for the first time or gathered in anew. Its own carnal members, i.e., those whose lives or opinions are carnal, it tolerates as chaff by which the corn is protected on the floor until it is separated from its covering. On this floor everyone voluntarily makes himself either corn or chaff. Therefore every man’s sin or error is tolerated until he finds an accuser or defends his wicked opinion with pertinacious animosity. Those who are excluded return by way of penitence, or in baleful liberty sink into wickedness as a warning to us to be diligent; or they cause schisms to exercise our patience; or they beget a heresy to try our intelligence or to quicken it. By such ways carnal Christians leave us, for they could neither be corrected nor endured…

(§12) …[W]e must hold fast the Christian religion and the communion of the Church which is Catholic, and is called Catholic not only by its own members but also by all its enemies. Whether they will or no, heretics and schismatics use no other name for it than the name of Catholic, when they speak of it not among themselves but with outsiders. They cannot make themselves understood unless they designate it by this name which is in universal use.

St. Augustine, Faith and the Creed (Ch. 10, §21):

(§21) …[W]e believe also in the Holy Church, [intending thereby] assuredly the Catholic. For both heretics and schismatics style their congregations churches. But heretics, in holding false opinions regarding God, do injury to the faith itself; while schismatics, on the other hand, in wicked separations break off from brotherly charity, although they may believe just what we believe. Wherefore neither do the heretics belong to the Church catholic, which loves God; nor do the schismatics form a part of the same, inasmuch as it loves the neighbor, and consequently readily forgives the neighbor’s sins, because it prays that forgiveness may be extended to itself by Him who has reconciled us to Himself, doing away with all past things, and calling us to a new life. And until we reach the perfection of this new life, we cannot be without sins. Nevertheless it is a matter of consequence of what sort those sins may be.

St. Augustine, Against the Fundamental Epistle of Manichaeus (§§5-6):

(§5) For in the Catholic Church, not to speak of the purest wisdom, to the knowledge of which a few spiritual men attain in this life, so as to know it, in the scantiest measure, indeed, because they are but men, still without any uncertainty (since the rest of the multitude derive their entire security not from acuteness of intellect, but from simplicity of faith)—not to speak of this wisdom, which you do not believe to be in the Catholic Church, there are many other things which most justly keep me in her bosom. The consent of peoples and nations keeps me in the Church; so does her authority, inaugurated by miracles, nourished by hope, enlarged by love, established by age. The succession of priests keeps me, beginning from the very seat of the Apostle Peter, to whom the Lord, after His resurrection, gave it in charge to feed His sheep, down to the present episcopate. And so, lastly, does the name itself of Catholic, which, not without reason, amid so many heresies, the Church has thus retained; so that, though all heretics wish to be called Catholics, yet when a stranger asks where the Catholic Church meets, no heretic will venture to point to his own chapel or house. Such then in number and importance are the precious ties belonging to the Christian name which keep a believer in the Catholic Church, as it is right they should, though from the slowness of our understanding, or the small attainment of our life, the truth may not yet fully disclose itself. But with you, where there is none of these things to attract or keep me, the promise of truth is the only thing that comes into play. Now if the truth is so clearly proved as to leave no possibility of doubt, it must be set before all the things that keep me in the Catholic Church; but if there is only a promise without any fulfillment, no one shall move me from the faith which binds my mind with ties so many and so strong to the Christian religion.

(§6) …For my part, I should not believe the gospel except as moved by the authority of the Catholic Church. So when those on whose authority I have consented to believe in the gospel tell me not to believe in Manichaeus [a heretic], how can I but consent?

St. Augustine, Epistle 43: To Glorius, Eleusius, the Two Felixes, Grammaticus, etc. (Ch. 1, §1):

(§1) The Apostle Paul has said: “A man that is an heretic after the first and second admonition reject, knowing that he that is such is subverted and sins, being condemned of himself.” [Tit. 3:10-11] But though the doctrine which men hold be false and perverse, if they do not maintain it with passionate obstinacy, especially when they have not devised it by the rashness of their own presumption, but have accepted it from parents who had been misguided and had fallen into error, and if they are with anxiety seeking the truth, and are prepared to be set right when they have found it, such men are not to be counted heretics…On this ground I wrote even to some of the chief of the Donatists, not indeed letters of communion, which on account of their perversity they have long ceased to receive from the undivided Catholic Church which is spread throughout the world, but letters of a private kind, such as we may send even to pagans.

St. Augustine, On Baptism, Against the Donatists (Book Four):

(Ch. 4, §6) …[J]ust as baptism is of no profit to the man who renounces the world in words and not in deeds, so it is of no profit to him who is baptized in heresy or schism; but each of them, when he amends his ways, begins to receive profit from that which before was not profitable, but was yet already in him…

(Ch. 21, §29) …I do not hesitate for a moment to place the Catholic catechumen, who is burning with love for God, before the baptized heretic; nor yet do we thereby do dishonor to the sacrament of baptism which the latter has already received, the former not as yet; nor do we consider that the sacrament of the catechumen is to be preferred to the sacrament of baptism, when we acknowledge that some catechumens are better and more faithful than some baptized persons. For the centurion Cornelius, before baptism, was better than Simon, who had been baptized. For Cornelius, even before his baptism, was filled with the Holy Spirit [Acts 10:44]; Simon, even after baptism, was puffed up with an unclean spirit…But since it is of no avail for salvation unless he who has baptism indeed in full perfection be incorporated into the Church, correcting also his own depravity, let us therefore correct the error of the heretics, that we may recognize what in them is not their own but Christ’s.

ST. VINCENT OF LÉRINS (died c. 445)

St. Vincent of Lérins, Commonitory (§§4-6):

(§4) I have often then inquired earnestly and attentively of very many men eminent for sanctity and learning, how and by what sure and so to speak universal rule I may be able to distinguish the truth of Catholic faith from the falsehood of heretical pravity; and I have always, and in almost every instance, received an answer to this effect: That whether I or anyone else should wish to detect the frauds and avoid the snares of heretics as they rise, and to continue sound and complete in the Catholic faith, we must, the Lord helping, fortify our own belief in two ways; first, by the authority of the Divine Law, and then, by the Tradition of the Catholic Church.

(§5) But here someone perhaps will ask, Since the canon of Scripture is complete, and sufficient of itself for everything, and more than sufficient, what need is there to join with it the authority of the Church's interpretation? For this reason—because, owing to the depth of Holy Scripture, all do not accept it in one and the same sense, but one understands its words in one way, another in another; so that it seems to be capable of as many interpretations as there are interpreters. For Novatian expounds it one way, Sabellius another, Donatus another, Arius, Eunomius, Macedonius, another, Photinus, Apollinaris, Priscillian, another, Iovinian, Pelagius, Celestius, another, lastly, Nestorius another. Therefore, it is very necessary, on account of so great intricacies of such various error, that the rule for the right understanding of the prophets and apostles should be framed in accordance with the standard of Ecclesiastical and Catholic interpretation.

(§6) Moreover, in the Catholic Church itself, all possible care must be taken, that we hold that faith which has been believed everywhere, always, by all. For that is truly and in the strictest sense Catholic, which, as the name itself and the reason of the thing declare, comprehends all universally. This rule we shall observe if we follow universality, antiquity, consent. We shall follow universality if we confess that one faith to be true, which the whole Church throughout the world confesses; antiquity, if we in no wise depart from those interpretations which it is manifest were notoriously held by our holy ancestors and fathers; consent, in like manner, if in antiquity itself we adhere to the consentient definitions and determinations of all, or at the least of almost all priests and doctors.

ST. FULGENTIUS OF RUSPE (c. 472/467-527/533)

St. Fulgentius of Ruspe, Rule of Faith (§§43-44)[4]:

(§43) …[A]nyone who receives the Sacrament of Holy Baptism in the name of the Father and of the Son and of the Holy Spirit, whether in the Catholic Church or in any heresy or schism, receives the complete Sacrament; but he will not have salvation which is the effect of the Sacrament if he receives the Sacrament outside the Catholic Church. Therefore, that person must return to the Church, not to receive the Sacrament of Baptism again, which no one must repeat in the case of any person already baptized, but in order that he receive eternal life in the Catholic community. Anyone who has received the Sacrament of Baptism but remained away from the Catholic Church is never prepared to obtain eternal life. Such a person, even if he is very generous with almsgiving and even pours out his blood for the name of Christ, because of the fact that in this life he has not held tightly to the unity of the Catholic Church, he will not have eternal salvation. Wherever Baptism can be of use to anyone, it is there that almsgiving can be of avail. Baptism indeed can exist outside the Church, but it can be of no avail except within the Church.

(§44) Therefore, only within the Catholic Church can the reception of Baptism and the works of mercy and the glorious confession of the name of Christ be of use to anyone—provided, however, one lives well in the Catholic Church.

St. Fulgentius of Ruspe, On the Forgiveness of Sins (Ch. 19, §§1-2)[5]:

(§1) Therefore, only in the Catholic Church is the forgiveness of sins given and received. This Church the bridegroom himself calls his one dove, his chosen one, which he founded upon a rock, to which he gave the keys of the kingdom of heaven, to which he also granted the power of binding and loosing, just as the Truth itself truthfully promised blessed Peter, saying, “You are Peter and upon this rock, I will build my Church and the gates of the netherworld shall not prevail against it. I will give you the keys to the kingdom of heaven. Whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.” [Matt. 16:18-19]

(§2) Whoever is outside this Church which has received the keys of the kingdom of heaven is not teaching the path to heaven but to hell; nor is he heading to the house of eternal life, but he is hurrying toward the punishment of eternal death; not only if he remains a pagan without baptism but also, even if he perseveres as a heretic, if he is baptized in the name of the Father and the Son and the Holy Spirit. Nor does one gain the true life because of the merit of baptism, if one is baptized in the name of the Father and of the Son and of the Holy Spirit whether within the Church or outside the Church, if one does not end this life still within the Catholic Church. Nor will one live because of the sacrament of the Church’s baptism, who has not held to the communion of the Church’s faith and charity. That one is saved by the sacrament of baptism whom the unity of charity will have held within the Catholic Church until the end of this present life.

ST. POPE GREGORY THE GREAT (c. 540-604)

St. Pope Gregory the Great, Moralia in Job (Part Four, Book 20, §15)[6]:

All heretics, when compared to the age of the Catholic Church, are fitly called ‘younger’ in time, because they went forth out of Her, not she out of them. Whence it is rightly also said by John, ‘They went out from us, but they were not of us: for if they had been of us, they would no doubt have continued with us.’ [1 John 2:19] For ‘they that are younger in time deride Holy Church,’ when they that went out from her, set at naught the words of Her instruction.

St. Pope Gregory the Great, Moralia in Job (Part Six, Book 35, §33)[7]:

(§33) But because there can be no innocence, no true obedience, in the manifold divisions of heretics, let those who come to the knowledge of the faith offer a lamb, but only one; and an earring, but only one. That is, let them come so minded as to abide innocent and obedient in the unity of Holy Church. For that which is ‘one’ cannot be divided by numbers, because also this very ‘one’ of which we are speaking, is not a number. That is, coming to Holy Church with innocence and obedience, let them offer such a mind as the schisms of sects cannot divide.

St. Pope Gregory the Great, Epistle 4 from Book 4: To Queen Theodelinda:

It has come to our knowledge by the report of certain persons that your Glory has been led on by some bishops even to such an offense against holy Church as to withdraw yourself from the communion of Catholic unanimity. Now the more we sincerely love you, the more seriously are we distressed about you, that you believe unskilled and foolish men, who not only do not know what they talk about, but can hardly understand what they have heard…Further, if anyone presumes to speak or think anything contrary to the faith of the said synod [Chalcedon], we detest his opinion, with interposition of anathema. Since then you know the integrity of our faith under the attestation of our conscience, it remains that you should never separate yourself from the communion of the Catholic Church, lest all those tears of yours, and all those good works should come to nothing, if they are found alien from the true faith.

ST. BEDE THE VENERABLE (c. 672/73-735)

St. Bede the Venerable, On the Temple (Book One)[8]:

(Ch. 1, §1): The house of God which king Solomon built in Jerusalem was made as a figure of the holy universal [“Catholic”] Church which, from the first of the elect to the last to be born at the end of the world, is daily being built through the grace of the king of peace, namely, its redeemer It is still partly in a state of pilgrimage from him on earth, and partly, having escaped from the hardships of its sojourn, already reigns with him in heaven, where, when the last judgment is over, it is to reign completely with him.

(Ch. 5, §3): The reason why the house of the Lord is built in the vision of peace is that the Church which is spread throughout the world consists in one and the same faith and fellowship of universal truth. For God is not in division of minds; rather his place is in peace and his dwelling in Sion. [Ps. 75:3]

SOURCES

[1]Origen, Homily 3 on Joshua (§5); Origen, Barbara J. Bruce, trans., The Fathers of the Church, Vol. 105: Origen, Homilies on Joshua (Washington, DC: The Catholic University of America Press, 2002), 50.

[2]St. Jerome, Commentary on Titus (3:10-11); St. Jerome, Thomas P. Scheck, trans., St. Jerome’s Commentaries on Galatians, Titus, and Philemon (Notre Dame, IN: University of Notre Dame Press, 2010), 346.

[3]St. Augustine, Of True Religion (§12); St. Augustine, J.H.S. Burleigh, trans., Of True Religion (Chicago: Henry Regnery Company, 1964), 12-13, 14.

[4]St. Fulgentius of Ruspe, To Peter on the Faith (§§43-44); St. Fulgentius of Ruspe, Robert B. Eno, S.S., trans., The Fathers of the Church, Vol. 95: Fulgentius, Selected Works (Washington, DC: The Catholic University of America Press, 1997), 88.

[5]St. Fulgentius of Ruspe, On the Forgiveness of Sins (Ch. 19, §§1-2); Id. 133-34.

[6]St. Pope Gregory the Great, Moralia in Job (Part Four, Book 20, §15); St. Pope Gregory the Great, Moralia in Job: Second Volume (Ex Fontibus Company, 2012), 431.

[7]St. Pope Gregory the Great, Moralia in Job (Part Six, Book 35, §33); St. Pope Gregory the Great, Moralia in Job: Third Volume (Ex Fontibus Company, 2012), 631.

[8]St. Bede the Venerable, Seán Connolly, trans., Bede: On the Temple (Liverpool: Liverpool University Press, 1995).