Chapter IX: How Liberation From Original Sin Takes Place.
CHAPTER IX: WHICH EXPLAINS HOW LIBERATION
FROM THIS SIN TAKES PLACE
§ 128. It remains to be explained how we are cleansed from that original stain. This happens in Baptism, which is “the washing of regeneration and of renewal” (Titus 3:5). Regeneration includes the remission of sins through the blood of Christ, which washes us of every sin. Renewal includes the mortification of the flesh and the beginning of new obedience, which is not completely perfect in every detail in this life because “the inner man is renewed day by day” (2 Cor. 4:16). But it will be perfected at some time in the future life when we will be whole, like the angels, and completely sinless. Thus the apostle teaches that the guilt of sin has been removed from the reborn (Rom. 8:21). Meanwhile, as far as depravity is concerned, original sin nevertheless remains (Rom. 7:17), and the devout mortify its deeds (Rom. 8:13) until they are restored into the full freedom of eternal life (v. 21).
Augustine (De peccat. merit. et remiss., bk. 2, ch. 7): “If perfect newness in the very soul, which is the interior man, happened in Baptism, the apostle would not say, ‘The inner man is being renewed day by day’ [2 Cor. 4:16]. Therefore he is not yet completely renewed, and to the extent that he is not yet renewed, he is under the old.” Again (on John, tractate 42): “ ‘Let sin not reign.’ He does not say, ‘Let sin not exist,’ but ‘Let it not reign.’ For as long as you live, it is necessary that sin exist in your members. At least let reigning be taken away from it; let what it orders not occur.”
The corrupt concupiscence which remains in the reborn is sin.
§ 129. Therefore the corrupt concupiscence which remains in the baptized and reborn has the true and proper nature of sin, as the apostle witnesses several times in clear words in the Epistle to the Romans, chs. 6–8. He frees us from the brute thunderbolt of the Council of Trent, which in session 5 denounces those who affirm this. 1 John 3:4: “Every lawlessness is sin.” But the corrupt concupiscence is lawlessness. For this reason, all the saints are compelled to pray for the forgiveness of sins (Ps. 32:6), and they complain that they are sold under sin (Rom. 7:14). They also pray to be freed from that wretched slavery of sin (v. 24). They admit that no one can boast that he is innocent before God (Exod. 34:7), and they pray earnestly that God not enter into judgment with them (Ps. 143:[2]). Surely, in regard to these two questions—namely, whether after Baptism anything that is truly and properly called sin remains in the flesh of the reborn and whether the impulses of concupiscence which are resisted through the Spirit are sins—regarding these questions, I say, we shall discuss them in more detail in the following treatise On Actual Sins [Commonplace XIII, §§ 36–79] and in our article On Baptism [Commonplace XXIII, §§ 128–64].