"Unto this end the Son of God was manifested." Ah, my brethren, all sinners are born of the devil, inasmuch as they are sinners. Adam was made by God: but when he consented to the devil, he was born of the devil; and all that he has begotten are as he was. With concupiscence itself we were born, and our birth comes of that condemnation, before we add to it debts of our own. If we are born with no sin, there is no reason for hastening with our infant children to baptism for their absolution. There are two births for your understanding, my brothers, of Adam and of Christ: two men, but of them one man is man, the other man is God. Through the man that is man we are sinners: through the Man that is God we are justified. One birth has cast us down to death; the other has raised us up to life. One draws sin along with it, the other delivers from sin. For to this end came Christ as man, that he might do away with the sins of man. "To this end the Son of God was manifested, that he mighty destroy the works of the devil."
St. Augustine, Later Works, Homilies on 1 John