On the Figurative Interpretation of Genesis:

“For who that has understanding will suppose that the first, and second, and third day, and the evening and the morning, existed without a sun, and moon, and stars? And that the first day was also without a sky? And who is so foolish as to suppose that God, after the manner of a husbandman, planted a paradise in Eden, towards the east, and placed in it a tree of life, visible and palpable, so that one tasting of the fruit by the bodily teeth obtained life? And again, that one was a partaker of good and evil by eating the fruit? And if God is said to walk in the paradise in the evening, and Adam to hide himself under a tree, I do not suppose that anyone doubts that these things figuratively indicate certain mysteries, the history having taken place in appearance, and now literally” – Fundamental Doctrines 4:16 (c. A.D. 225)

“The text said that ‘there was evening and there was morning’ it did not say
‘the first day,’ but said ‘one day.’ It is because before the world existed there was not yet time. But time begins to exist with the following days.” –Homilies on Genesis I (c. A.D. 242)

On Confession:

“[A final method of forgiveness], albeit hard and laborious, is the remission of sins through penance, when the sinner . . . does not shrink from declaring his sin to a priest of the Lord and seeking medicine . . . which the apostle James says: ‘If there is anyone sick, let him call the presbyters of the Church, and let them impose hands upon him,
anointing him with oil in the name of the Lord; and the prayer of faith will save the sick man, and if he be in sins, they shall be forgiven him.’” –Homilies on Leviticus 2:4 (Written 248 A.D.)

“For the one who incites us to sin is the very one who will accuse us when we have sinned. If, therefore, we anticipate him in life, and become the accusers of ourselves, we will escape the malice of the devil, our enemy and accuser… You see, then, that the confession of sin merits the remission of sin. For if we precede the devil in making our accusation, he will not be able to accuse us. If we become our own accusers, it profits us unto salvation.” – Homilies on Leviticus 3:4 (244 A.D.)

“If we have sinned we ought to say: ‘My sins I have made known to you and my wickedness I have not hidden. I accuse myself of injustice to the Lord.’ If we do this and reveal our sins not only to God, but also to those who are able to remedy our wounds and sins, then our sins will be blotted out.” – Homilies on Luke 17. (Written in 233 A.D.)

“Hear the rule which the law enjoins: ‘If someone has sinned, then he shall confess his sin.’ There is something wonderful hidden in this, whereby confession of sins is commanded. For they are to be confessed, whatever kind they may be; and all that we do must be brought
forward in public. Whatever we have done in secret, whatever sin we have committed by word alone or in our thoughts- all must be made public, all must be brought forward.” – Homilies on Leviticus 3:4 (Written 244 A.D.)

On the Intercession of Saints:

“But not the high priest [Christ] alone prays for those who pray sincerely, but also the angels . . . as also the souls of the saints who have already fallen asleep.” –Prayer 11 (Written in 233 A.D.)

On Mary’s Perpetual Virginity:

“The Book [the Protoevangelium] of James [records] that the brethren of Jesus were sons of Joseph by a former wife, whom he married before Mary. Now those who say so wish to preserve the honor of Mary in virginity to the end, so that body of hers which was appointed to minister to the Word . . . might not know intercourse with a man after the Holy Spirit came into her and the power from on high overshadowed her. And I think it in harmony with reason that Jesus was the first fruit among men of the purity which consists in [perpetual] chastity, and Mary was among women. For it were not pious to ascribe to any other than to her the first fruit of virginity.” –Commentary on Matthew 2:17 (Written 248 A.D.)

“And the Lord spoke to Moses saying, ‘A woman, if she has received seed, and if she shall bear a male child, shall be unclean for seven days.’ The expression ‘if she has received seed’ placed before ‘bear a male child’ would seem superfluous. But I wonder whether the statement was made in this manner, lest Mary, who would bear a male child without receiving seed, should otherwise be thought to be unclean by reason of birth of the Savior… Yet Mary would still be understood to be clean for she was not simply a woman, but a Virgin.” – Homilies on Leviticus 8.2. (Written 244 A.D.)

On the Real Presence:

“Formerly, in an obscure way, there was manna for food; now, however, in full view, there is the true food, the flesh of the Word of God, as he himself says: ‘My flesh is true food, and my blood is true drink’ [John 6:55]” –Homilies on Numbers 7:2 (Written 248 A.D.)

On Works & Merit:

“The holy Apostles, in preaching the faith of Christ, treated with utmost clarity certain matters they believed necessary to the salvation of believers. It is taught also that the soul shall, after its departure from this world, be rewarded according to its merits. It is destined to obtain either an inheritance of eternal life, if it’s deeds have procured this for it, or to be delivered unto eternal fire and punishment, if the guilt of its crimes brought it down to this.”  –Fundamental Doctrines Preface 3:5 (Written 220 A.D.)

On Purgatory:

“For if on the foundation of Christ you have built not only gold, silver and precious stones (I Cor. 3:12-15) but also wood, hay and stubble, what do you expect when the soul shall be separated from the body? Would you enter into heaven with your wood and hay and stubble and thus defile the kingdom of God;
or on account of these hindrances would you remain without and receive no reward for your gold and silver and precious stones? Neither is this just. It remains then that you be
committed to the fire which will burn the light materials; for our God to those who can comprehend heavenly things is called a cleansing fire. But this fire consumes not the creature,
but what the creature has himself built; wood, hay and stubble. It is manifest that the fire destroys the wood of our transgressions and then returns to us the reward of our good works.” -P.G., XIII, col. 445, 448

“Even the punishment, which is said to be inflicted by means of fire, is understood to be applied remedially, as taught by Isaiah, who does indeed speak thus in regards to Israel; ‘The Lord will wash away the filth of the sons and daughters of Sion and will purify them with the spirit of judgment and of burning. . .’ And of the Chaldeans, he speaks thus; ‘You have coals of fire, sit upon them and they will be of help to you.’ In other passages, he says; ‘The Lord will sanctify in a burning fire.’” –Fundamental Doctrines 2:10:6 (Written 220 A.D.)

“For if, because of diseases we contracted, we must occasionally, for the health of the body, make use of a harsh curative; and if the nature of the disease demands it… the virulence must at last be cauterized by fire; how much more understandable is it that God, our Physician, desiring to cure the diseases of our souls, which were contracted by a variety of sins and crimes, should likewise employ such punitive cures, even punishment by fire, for the health of our souls!” – Fundamental Doctrines 2.10.6 (Written 220 A.D.)

“Thus, when the soul is found to be outside the order, structure, or harmony in which, for its own sake, it was created by God. it must be supposed that it will bear the agonizing penalty of its own dissension and will feel the punishment of its own inconsistency and disorderliness. When this tearing asunder of the soul has been accomplished by means of application of fire, no doubt it will afterwards be solidified into a firmer structure and restoration of itself.” – Fundamental Doctrines 2.10.3 (Written in 220 A.D.)

On Infant Baptism & Apostolic Tradition:

“The Church received from the apostles the tradition of giving baptism even to infants. The apostles, to whom were committed the secrets of the divine sacraments knew there are in everyone innate strains of [original] sin, which must be washed away through water and the Spirit.” –Commentaries on Romans 5:9 [A.D. 248]).

On Faith Alone:

“Whoever dies in his sins,
even if he profess to believe in Christ, does not truly believe in him; and even if that which exists without works be called faith, such faith is dead in itself, as we read in the epistle bearing the name of James.” –Commentaries on John 19:6 (Written 226- A.D.)

On the Necessity of Baptism:

“It is not possible to receive forgiveness of sins without baptism.” –Exhortation to the Martyrs 30 [A.D. 235]

“Every soul that is born into flesh is soiled by the filth of wickedness and sin. . . In the Church, baptism is given for the remission of sins, and, according to the usage of the Church, baptism is given even to infants. If there were nothing in infants which
required the remission of sins and nothing in them pertinent to forgiveness, the grace of baptism would seem superfluous.” –Homilies on Leviticus 8:3 (Written 248 A.D.)

On the Papacy:

“[I]f we were to attend carefully to the Gospels, we should also find, in relation to those things which seem to be common to Peter . . . a great difference and a preeminence in the things [Jesus] said to Peter, compared with the second class [of apostles]. For it is no small difference that Peter received the keys not of one heaven but of more, and in order that whatsoever things he binds on earth may be bound not in one heaven but in them all, as compared with the many who bind on earth and loose on earth, so that these things are bound and loosed not in [all] the heavens, as in the case of Peter, but in one only; for they do not reach so high a stage with power as Peter to bind and loose in all the heavens.” –Commentary on Matthew 13:31 [A.D. 248]

“Look at Peter, the great foundation of the Church, that most solid of rocks, upon whom Christ built the Church [Matt. 16:18]. And what does our Lord say to him? ‘Oh you of little faith,’ he says, ‘why do you doubt?’ [Matt. 14:31]” –Homilies on Exodus 5:4 (Written 248 A.D.)

“Peter, upon whom is built the Church of Christ, against which the gates of hell shall not prevail, left only one Epistle of acknowledged genuinity. Let us concede also a second, which, however, is doubtful.” –Commentaries on John (Written 244 A.D.) [cited by Eusebius in History of the Church 6:25]

Scripture Relies On Sacred Tradition:

“Among the four Gospels, which are the only indisputable ones in the Church of God under heaven, I have learned by tradition that the first was written by Matthew, who was once a publican, but afterwards an apostle of Jesus Christ, and it was prepared for the converts from Judaism and published in the Hebrew language. The second was that of Mark, who composed it under Peter’s guidance. . . The third was the Gospel praised by Paul, that of Luke, written for gentile converts. Last of all, was that of John’s.” –Commentaries on Matthew (Written 244 A.D.)
[cited by Eusebius in History of the Church 6:25:3]

“Moreover, it is of ecclesiastical teaching that the Scriptures were written through the Spirit of God, and that they have not only that meaning which is quite apparent, but also another which escapes most. For the words which are written are the forms of certain mysteries, and the images of divine things. In this matter the opinion of the whole Church is one: that the whole Law is indeed spiritual; the spiritual meaning which the Law conveys, however, is not known to all, but only to those on whom the grace of the Holy Spirit is bestowed in the word of wisdom and knowledge.” –Fundamental Doctrines 1:Preface:8 (Written 220 A.D.)

“Some of these things have been preserved in the apocryphal books. For an example, we shall give the story about Isaiah, witnessed by the epistle to the Hebrews but not written in any of the canonical books of the Old Testament.” –Letter to Africanus 9 (Written ca. 235 A.D.)

On Apostolic Succession & Tradition:

“Although there are many who believe that they themselves hold to the teachings of Christ, there are yet some among them who think differently from their predecessors. The teaching of the Church has indeed been handed down through an order of succession from the apostles and remains in the churches even to the present time. That alone is to be believed as the truth which is in no way at variance with ecclesiastical and apostolic tradition.” – Fundamental Doctrines 1:2 (Written 225 A.D.)

On Sunday Worship:

“Hence it is not possible that the [day of] rest after the Sabbath should have come into existence from the seventh [day] of our God. On the contrary, it is our Savior who, after the pattern of his own rest, caused us to be made in the likeness of his death, and hence also of his resurrection.” Commentary on John 2:28 [A.D. 229]

On Priestly Celibacy:

“Not fornication only, but even marriages make us unfit for ecclesiastical honors; for neither a bishop, nor a presbyter, nor a deacon, nor a widow is able to be twice married.” –Homilies on Luke17 [A.D. 234]

“Certain ones among Christians, from a desire of excelling in chastity, and in order to worship God in greater purity, refrain from even such pleasures as are in accord with the law (marital relations).” – Against Celsus 1:26
(Written 248 A.D.)

“The Savior said to them, teaching us that absolute chastity is a gift from God, not obtained from ascetic practice alone, but given by God with prayer: ‘Not all can accept this teaching: only to those to whom it has been given.’ (Matt 19:11). . . If we believe the Scriptures, why then do we lay hold of this saying and not attend to this: ‘Ask and it shall be given you!’ (Matt 7:7). . . God, therefore, will give the good gift, perfect purity in celibacy and chastity, to those who ask him with whole faith, and prayers without ceasing.” –Commentaries on Matthew 14:25. (Written 244 A.D.)

On Salvation Outside The Church:

“If someone from this people wants to be saved, let him come into this house so that he may be able to attain his salvation. . . . Let no one, then, be persuaded otherwise, nor let anyone deceive himself: Outside of this house, that is, outside of the Church, no one is saved; for, if anyone should go out of it, he is guilty of his own death.” –Homilies on Joshua 3:5 [A.D. 250]