For Christ also said, ‘Except ye be born again, ye shall not enter into the kingdom of heaven.’ Now, that it is impossible for those who have once been born to enter into their mothers’ wombs, is manifest to all. And how those who have sinned and repent shall escape their sins, is declared by Esaias the prophet, as I wrote above; he thus speaks: ‘Wash you, make you clean; put away the evil of your doings from your souls; learn to do well…And though your sins be as scarlet, I will make them white like wool; and though they be as crimson, I will make them white as snow…And for this [rite] we have learned from the apostles this reason. Since at our birth we were born without our own knowledge or choice, by our parents coming together, and were brought up in bad habits and wicked training; in order that we may not remain the children of necessity and of ignorance, but may become the children of choice and knowledge, and may obtain in the water the remission of sins formerly committed, there is pronounced over him who chooses to be born again, and has repented of his sins, the name of God the Father and Lord of the universe; he who leads to the layer the person that is to be washed calling him by this name alone…And this washing is called illumination, because they who learn these things are illuminated in their understandings. And in the name of Jesus Christ, who was crucified under Pontius Pilate, and in the name of the Holy Ghost, who through the prophets foretold all things about Jesus, he who is illuminated is washed.”
Justin Martyr, First Apology, 61 (A.D. 110-165).
“Moreover, the things proceeding from the waters were blessed by God, that this also might be a sign of men’s being destined to receive repentance and remission of sins, through the water and laver of regeneration,–as many as come to the truth, and are born again, and receive blessing from God.”
Theopilus of Antioch, To Autolycus, 2:16 (A.D. 181).
” ‘And dipped himself,’ says [the Scripture], ‘seven times in Jordan.’ It was not for nothing that Naaman of old, when suffering from leprosy, was purified upon his being baptized, but it served as an indication to us. For as we are lepers in sin, we are made clean, by means of the sacred water and the invocation of the Lord, from our old transgressions; being spiritually regenerated as new-born babes, even as the Lord has declared: ‘Except a man be born again through water and the Spirit, he shall not enter into the kingdom of heaven.'”
Irenaeus, Fragment, 34 (A.D. 190).