This reasoning will carry more weight, after I have collected the mass of Scripture testimonies which I have undertaken to adduce. We have already quoted: “I came not to call the righteous, but sinners.” To the same purport [the Lord] says, on entering the home of Zaccheus: “To-day is salvation come to this house, forsomuch as he also is a son of Abraham; for the Son of man is come to seek and to save that which was lost.” The same truth is declared in the parable of the lost sheep and the ninety and nine which were left until the missing one was sought and found; as it is also in the parable of the lost one among the ten silver coins. Whence, as He said, “it behoved that repentance and remission of sins should be preached in His name among all nations, beginning at Jerusalem.” Mark likewise, at the end of his Gospel, tells us how that the Lord said: “Go ye into all the world, and preach the gospel to every creature. He that believeth, and is baptized, shall be saved; but he that believeth not shall be damned.” Now, who can be unaware that, in the case of infants, being baptized is to believe, and not being baptized is not to believe? From the Gospel of John we have already adduced some passages. However, I must also request your attention to the following: John Baptist says of Christ, “Behold the Lamb of God, Behold Him which taketh away the sin of the world;” and He too says of Himself, “My sheep hear my voice, and I know them, and they follow me: and I give unto them eternal life; and they shall never perish.” Now, inasmuch as infants are only able to become His sheep by baptism, it must needs come to pass that they perish if they are not baptized, because they will not have that eternal life which He gives to His sheep. So in another passage He says: “I am the way, the truth, and the life; no man cometh unto the Father, but by me.”
Reproduced in full. Translation: Nicene and Post-Nicene Fathers, series 1, vol. 5 (Schaff, 1887), public domain (Public domain).