ca. 70 A.D., Didache or Teaching of the Twelve Apostles
4 In church, make confession of your faults, and do not come to your prayers with a bad conscience.
This is the Way of Life. …
14 Assemble on the Lord’s Day [i.e., Sunday], and break bread and offer the Eucharist; but first make confession of your faults, so that your sacrifice may be a pure one. Anyone who has a difference with his fellow is not to take part with you until they have been reconciled, so as to avoid any profanation of your sacrifice. For this is the offering of which the Lord has said, Everywhere and always bring me a sacrifice that is undefiled, for I am a great king, says the Lord, and my name is the wonder of the nations (Mal. 1:11, 14).
— Mortal sin —
16 Be watchful over your life; never let your lamps go out or your loins be ungirt, but keep yourselves always in readiness, for you can never be sure of the hour when our Lord may be coming. Come often together for spiritual improvement; because all the past years of your faith will be no good to you at the end, unless you have made yourselves perfect (Maxwell Staniforth, Early Christian, pp. 193, 195, 197).
ca. 96 A.D., Pope Saint Clement, fourth Bishop of Rome, disciple of the Apostles Peter and Paul, Letter to the Corinthians
51:1 For whatever our transgressions, and whatever we have done through the attacks of the adversary, let us pray that we may be forgiven. … For it is good for a man to confess his failings rather than to harden his heart.
— ca. 100 A.D., Death of Saint John, the last of the Apostles —
ca. 107 A.D., Saint Ignatius, Bishop of Antioch, disciple of the Apostle John, Letter to the Philadelphians
— Mortal sin—
8:1 [W]here there is division and anger, God does not dwell. The Lord, however, forgives all who repent, if their repentance leads to the unity of God and to the council of the bishop.
ca. 150 A.D., Hermas, brother of Pope Saint Pius, The Shepherd
— Mortal sin —
Vis. 3:8:7 “And yet to these [sinners] also,” [the shepherd] continued, “repentance is possible. You see,” he said, “that some of them have repented, and there is still remaining in them,” he continued, “a hope of repentance. And as many of them,” he added, “as have repented, shall have their dwelling in the tower [i.e., the Church]. And those of them who have been slower in repenting shall dwell within the walls. And as many as do not repent at all, but abide in their deeds, shall utterly perish. … But if any one relapse into strife, he will be cast out of the tower, and will lose his life. Life is the possession of all who keep the commandments of the Lord."
ca. 156 A.D., Saint Justin the Martyr, Fragment
— Mortal sin —
Eternal fire has been prepared for him as he apostatized from God of his own free-will, and likewise for all who unrepentant continue in the apostasy, he now blasphemes, by means of such men, the Lord who brings judgment [upon him] as being already condemned, and imputes the guilt of his apostasy to his Maker, not to his own voluntary disposition. (Irenaeus, Heresies 5:26:1)
ca. 185 A.D., Saint Irenaeus, Bishop of Lyons, disciple of Saint Polycarp of Smyrna, Against Heresies
— Mortal sin—
1:10:1 For the Church … has received from the Apostles and from their disciples the faith in … [Christ Jesus our Lord’s] coming from heaven in the glory of the Father to re-establish all things (Eph. 1:10); … in order that to Jesus Christ our Lord and God and Savior and King, in accord with the approval of the invisible Father, every knee shall bend of those in heaven and on earth and under the earth, and that every tongue shall confess Him (Phil. 2:10-11), and that He may make just judgment of them all; and that He may send apostates, and the impious, unjust, lawless and blasphemous among men, into everlasting fire; and that He may grant life, immortality, and surround with eternal glory the just and the holy, and those who have kept His commands and who have persevered in His love, either from their beginning or from their repentance. …
1:13:7 [The gnostic disciples of Marcus] have deluded many women in our own district of the Rhone, by saying and doing such things. Their consciences branded as with a hot iron (1 Tim. 4:2), some of these women make a public confession; but others are ashamed to do this, and in silence, as if withdrawing from themselves the hope of the life of God, they either apostatize entirely or hesitate between the two courses.
203 A.D., Tertullian, Repentance
9:3-6 Thus, confession is a discipline for man’s prostration and humiliation, enjoining a manner, even as regards dress and food, conducive to mercy. It commands one to lie in sackcloth and ashes, to cover the body with mourning, to cast the spirit down in sorrow, to exchange the sins which have been committed for a demeanor of sorrow; to take no other food or drink except what is plain, not, of course, for the sake of the stomach, but for the sake of the soul; and most of all, to feed prayers on fasting; to groan, to weep and wail day and night to the Lord your God; to bow before the presbyters, to kneel before God’s refuge places, and to beseech all the brethren for the embassy of their own supplication.
Confession is all of this, so that it may excite repentance; so that it may honor God by fear and danger; so that it may, by its own pronouncement against the sinner, stand in place of God’s indignation; and so that it may by temporal mortification, I will not say frustrate, but rather expunge the eternal punishments. Therefore, while it abases a man, it raises him; while it covers him with squalor, the more does it cleanse him; while it condemns, it absolves. In so far as you do not spare yourself, the more, believe me, will God spare you! …
— Mortal sin —
10:1 Most men, however, either flee from this work [of confession], as being an exposure of themselves, or they put it off from day to day. I presume they are more mindful of modesty than of salvation, like those who contract a disease in the more shameful parts of the body and shun making themselves known to the physicians; and thus they perish along with their own bashfulness.
ca. 215 A.D., Saint Hippolytus of Rome, Bishop of Pontus, disciple of Irenaeus, The Apostolic Tradition
3:4 [The bishop consecrating a new bishop shall pray thus, saying:] “Father ‘who knowest the hearts [of all]’ (Acts 1:24) grant upon this Thy servant whom thou hast chosen for the episcopate to feed Thy holy flock (Acts 20:28; 1 Pet. 5:2) and serve as Thine high priest, that he may minister night and day, …
3:5-6 “And that by the high priestly Spirit he may have authority ‘to forgive sins’ according to Thy command (John 20:23)."
ca. 241 A.D., Origen, disciple of Clement of Alexandria, Homilies on the Psalms
2:6 For I confess my wickedness (Ps. 37 [38]:19). We have often spoken a denunciation of our wickedness: that is, we have often made a confession of sin. Look, then, to what Divine Scripture teaches us: that sin is not to lie hidden within us. Perhaps there are some who have an undigested mass of food shut up within them, or an abundance either of a humor or phlegm remaining in the stomach where it weighs upon them heavily and to their discomfort. If they vomit it out, they experience relief. It is the same with those who have sinned. If, indeed, they conceal their sin and keep it within them, they will suffer an internal urging, and may come close to being suffocated by the phlegm or humor of sin. If, however, a man in such a circumstance becomes his own accuser, as soon as he accuses himself and confesses, he vomits out his fault and puts in order what was the whole cause of his illness.
Only be careful and circumspect in regard to whom you would confess your sins. Test first the physician to whom you would expose the cause of your illness. See whether he knows to seem weak with one who is weak, to weep with one who weeps, and whether he is acquainted with the art of consoling and comforting. Finally, when he has shown himself to be a physician both learned and merciful, do whatever he might tell you, and follow whatever counsel he may give. If after much deliberation he has understood the nature of your illness and judges that to be cured it must be exposed in the assembly of the whole church, follow the advice of that expert physician, and thereby others may perhaps be able to be edified, while you yourself are the more easily healed.
ca. 245 A.D., Origen, Homilies on Leviticus
2:4 - 3:4 [A final method of forgiveness], albeit hard and laborious [is] the remission of sins through penance, when the sinner washes his pillow in tears, when his tears are day and night his nourishment, and when he does not shrink from declaring his sins to a priest of the Lord and from seeking medicine, after the manner of him who says, “I said, ‘To the Lord I will accuse myself of my iniquity’, and you forgave the disloyalty of my heart” (Ps. 31 [32]:5). In this way there is fulfilled that too, which the Apostle James says: “If, then, 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” (Jas. 5:14-15).
Hear the rule which the Law enjoins: “If someone of the aforementioned shall have sinned,” it says, “he shall confess the sin which he sinned” (cf. Lev. 5:5). 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 even in our secret thoughts — all must be made public, all must be brought forward. It will indeed be brought forward by him who is both the accuser of sin and the instigator thereof. For that one who now 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 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. But if we wait until the devil has accused us, that accusation will deliver us to punishment.
250 A.D., Saint Cyprian, Bishop of Carthage, Letter to His Clergy
— Venial sin —
16 [9]:2 Although for lesser [i.e., venial] sins it is required that sinners do penance for a just time, after which, according to the rule of discipline, they may come to confession and, through the imposition of hands by the bishop and clergy, may receive the right of communication [i.e., Holy Communion], now, in an unpropitious time and while the persecution continues, when peace is not yet restored to the Church itself, they are being admitted to communication, and the offering [i.e., Eucharist] is made in their name; and, not yet having made a confession of sin, not yet having had hands imposed upon them by the bishop and clergy, the Eucharist is given to them, in spite of what is written: “Whoever shall eat the Bread or drink the Cup of the Lord unworthily, will be guilty of the Body and Blood of the Lord” (1 Cor. 11:27). …
18 [12]:1 Inasmuch as I find that there is not yet an opportunity of coming to you, and the Summer has already begun — a season disturbed by continual and grave illnesses — I think that we must deal with our brethren. Therefore, … if they should be seized by some misfortune or dangerous illness at a time when my return is not expected, then, before whatever presbyter is present, or if a presbyter is not found and death begins to be imminent, even before a deacon they are permitted to make their confession of sin, so that a hand may be imposed upon them in penance and they may come to the Lord with … peace.