The Early Church Fathers on Confession
Here are some quotes from early church fathers which show the sacramental tradition of the Mystery of Confession’s unbroken lineage from the earliest days of the Christian church.
Didache 4:14; 14:1
As early as 70 AD
Confess your sins in church, and do not go up to your prayer with an evil conscience. This is the way of life…. On the Lord’s Day gather together, break bread, and give thanks, after confessing your transgressions so that your sacrifice may be pure.

St. Irenaeus of Lyons
180 AD
Against Heresies 1:22
[The gnostic disciples of Marcus] have deluded many women…Their consciences have been branded as with a hot iron [cf. 1 Tim 4:1ff]. 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.

Tertullian of Carthage
200 AD
On Repentance 10:1,6
[Regarding confession, some] flee from this work 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. Why do you flee from the partners of your misfortunes as you would from those who deride? The body is not able to take pleasure in the trouble of one of its members. It must necessarily grieve as a whole and join in laboring for a remedy….With one and two individuals, there is the Church [cf. Matt 18:17ff]; and the Church indeed is Christ. Therefore, when you cast yourself at the knees of the brethren, you are dealing with Christ, you are entreating Christ.

Origen of Alexandria
c. 244 AD
Homily on Leviticus 2:4
In addition to these [kinds of forgiveness of sins], albeit hard and laborious: the remission of sins through penance…when he [the sinner] does not shrink from declaring his sin to a priest of the Lord and from seeking medicine….In this way there is fulfilled that too, which the Apostle James says: “If, then, there is anyone sick, let him call the presbyters [where we get priests] 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 [James 5:14-15].”

St. Cyprian of Carthage
250 AD
The Lapsed 15:1-3; 28
The Apostle likewise bears witness and says: ….”Whoever eats the bread and drinks the cup of the Lord unworthily will be guilty of the body and blood of the Lord” [1 Cor 11:27]. But [the impenitent] spurn and despise all these warnings; before their sins are expiated, before they have made a confession of their crime, before their conscience has been purged in the ceremony and at the hand of the priest…they do violence to his body and blood, and with their hands and mouth they sin against the Lord more than when they denied him.
….Of how much greater faith and salutary fear are they who…confess their sins to the priests of God in a straightforward manner and in sorrow, making an open declaration of conscience. God cannot be mocked or outwitted, nor can he be deceived by any clever cunning….Indeed, he but sins the more if, thinking that God is like man, he believes that he can escape the punishment of his crime by not openly admitting his crime….I beseech you, brethren, let everyone who has sinned confess his sin while he is still in this world, while his confession is still admissible, while the satisfaction and remission made through the priests are still pleasing before the Lord.

St. Athanasius of Alexandria
295 – 373 AD
On the Gospel of Luke 19
Just as a man is enlightened by the Holy Spirit when he is baptized by a priest, so he who confesses his sins with a repentant heart obtains their remission from the priest.

St. Basil the Great
330 – 379 AD
Rules Briefly Treated 288
It is necessary to confess our sins to those to whom the dispensation of God’s mysteries [i.e. the Sacraments] is entrusted [i.e. priests]. Those doing penance of old are found to have done it before the saints. It is written in the Gospel that they confessed their sins to John the Baptist [Matt 3:6]; but in Acts they confessed to the Apostles, by whom also all were baptized [Acts 19:18].

St. Augustine of Hippo
c. 354 – 430 AD
Let this be in the heart of the penitent: when you hear a man confessing his sins, he has already come to life again; when you hear a man lay bare his conscience in confessing, he has already come forth from the sepulchre; but he is not yet unbound. When is he unbound? By whom is he unbound? “Whatever you loose on earth,” He says, “shall be loosed also in heaven” [Mt 16:19; 18:18; Jn 20:23]. Rightly is the loosing of sins able to be given by the Church… (Psalms 101:2:3)
Yet those who do penance in accord with the kind of sin they have committed are not to despair of receiving God’s mercy in the Holy Church, for the remission of their crimes, however serious. (Echiridian 17:65)
Iniquity, however, sometimes makes such progress in men that even after they have done penance and after their reconciliation to the altar they commit the same or more grievous sins….and although that place of penance in the Church is not granted them, God will not be unmindful of His patience in their regard….(Letters 153:3:7)
There have been those who would say that no penance is available for certain sins; and they have been excluded from the Church and have been made heretics. Holy Mother Church is not rendered powerless by any kind of sin. (Sermons 352:9)

St. Ambrose
c. 333 – 397 AD
Penance 2:2:12
But what was impossible was made possible by God, who gave us so great a grace. It seemed likewise impossible for sins to be forgiven through penance; yet Christ granted even this to His Apostles, and by His Apostles it has been transmitted to the offices of priest.

St. Jerome
c. 347 – 420 AD
Commentary on Matthew 3:16-19
Just as in the Old Testament [ibi] the priest makes the leper clean or unclean, so in the New Testament [hic] the bishop and presbyter [i.e. priest] binds or looses not those who are innocent or guilty, but by reason of their office, when they have heard various kinds of sins, they know who is to be bound and who loosed.

Theodore Of Mopsuestia
c. 428 AD
Catechetical Homilies 16
This is the medicine for sins, established by God and delivered to the priests of the Church, who make diligent use of it in healing the afflictions of men. You are aware of these things, as also of the fact that God, because He greatly cares for us, gave us penitence and showed us the medicine of repentance; and He established some men, those who are priests, as physicians of sins. If in this world we receive through them healing and forgiveness of sins, we shall be delivered from the judgment that is to come. It behooves us, therefore, to draw near to the priests in great confidence and to reveal to them our sins; and those priests, with all diligence, solicitude, and love, and in accord with the regulations mentioned above, will grant healing to sinners. [The priests] will not disclose the things that ought not be disclosed; rather, they will be silent about the things that have happened, as befits true and loving fathers [cf. 1 Thess 2:11; 1 Cor 4:15] who are bound to guard the shame of their children while striving to heal their bodies.

St. John Chrysostom
c. 344 – 407 AD
Homilies on John 86:4
Priests have received a power which God has given neither to angels nor to archangels. It was said to them: “Whatsoever you shall bind upon earth shall be bound in heaven; and whatsoever you shall loose, shall be loosed” [Matt 18:18]. Temporal rulers have indeed the power of binding; but they can bind only the body. Priests, however, can bind with a bond which pertains to the soul itself, and transcends the very heavens…Whatever priests do here on earth, God will confirm in heaven, just as the master ratifies the decision of his servants. Did He not give them all the powers of heaven?
“Whose sins you shall forgive,” He says, “they are forgiven them: whose sins you shall retain, they are retained” [John 20:23].
What greater power is there than this? …The Father has given all the judgment to the Son. And now I see the Son placing all this power in the hands of men. They are raised to this dignity as if they were already gathered up to heaven, elevated above human nature, and freed of its limitations….The priests of Judaism had power to cleanse the body from leprosy — or rather, not to cleanse it at all, but to declare a person as having been cleansed. And you know how much contention there was even in those times to obtain the priestly office. Our priests have received the power not of treating with the leprosy of the body, but with spiritual uncleanness; not of declaring cleansed, but of actually cleansing…What mean-souled wretch is there who would despise so great a good? None, I dare say, unless he be urged on by a devilish impulse….God has given to priests powers greater than those given to our parents; and the differences between the powers of these two is as great as the difference between the future life and the present….Our parents begot us to temporal existence; priests beget us to the eternal. The former are not able to ward off from their children the sting of death, nor prevent the attack of disease; yet the latter often save the sick and perishing soul — sometimes by imposing a lighter penance, sometimes by preventing the fall. Priests accomplish this not only by teaching and admonishing, but also by the help of prayer. Not only at the time of our regeneration [at Baptism], but even aftward they have the authority to forgive sins….
“Is there anyone among you sick? Let him call in the priests of the church, and let us pray over him, anointing him with oil in the name of the Lord. And the prayer of faith shall save the sick man, and the Lord shall raise him up, and if he have committed sins, he shall be forgiven” [James 5:14-15]. (The Priesthood 3:5:182-4; 3:6:190-6)
…Great is the dignity of priests. “Whose sins you forgive,” He says, “they are forgiven them” [John 20:23]…The things that are placed in the hands of the priest, it belongs to God alone to give…. Neither angel nor archangel is able to do anything in respect to what is given by God; rather, Father and Son and Holy Spirit manage it all; but the priest lends his own tongue and presents his own hand. Nor would it be just, if those who draw near in faith to the symbols of our salvation were to be harmed by the wickedness of another. (Homilies on John 86:4)

Pope Leo the Great
c. 459 AD
Letter of Pope Leo I to the Bishops of Campania, Samnium and Picenum dated March 6, 459 AD
I decree also that that presumption contrary to the apostolic regulation, which I recently learned is being committed by some in an illegal usurpation, is by all means to cease. With regard to penance, certainly what is required of the faithful is not that the nature of individual sins be written in a document and recited in a public profession, since it is sufficient that the guilt of consciences be indicated to priests alone in a secret confession. For although that fullness of faith may seem to be praiseworthy which, for fear of God, is not afraid to blush before men, nevertheless, because the sins of all are not of such kind that those who seek Penance do not fear to make them public, such an unapproved custom is to cease.