Repentance belongs only to sins, not to good deeds

But if people had God, and therefore reason as well, they would first weigh what repentance deserves. They would never use it as a device for perverse correction. They would at least set a limit to their repenting, because they would also hold a limit to their sinning, since they fear the Lord. But where there is no fear of God, there is likewise no amendment. Where there is no amendment, repentance is necessarily empty, because it lacks the fruit for which God sowed it, namely human salvation.

For after so many and such great sins of human recklessness, begun with Adam the first of our race, after man was condemned along with the world's endowment, after he was cast out of paradise and made subject to death, God then hastened back to his own mercy. From that point on he dedicated repentance in himself. The sentence of his former wrath was rescinded, and he covenanted to forgive his own work and image. And so he gathered a people to himself and nourished them with many gifts of his goodness. Though he found them utterly ungrateful time and again, he always urged them to repentance. Through the mouths of all the prophets he spoke, soon promising the grace with which he would illuminate the whole world through his Spirit at the end of the ages. He commanded the baptism of repentance to go before, so that if he called any through grace to the promise destined for Abraham's seed, he might first prepare them through the sealing of repentance.

John the Baptist does not keep silent. He says, "Begin repentance, for salvation is now drawing near to the nations," meaning the Lord who brings it according to God's promise. Ministering to him, John appointed repentance to be set over minds that needed cleansing, so that whatever old error had defiled, whatever ignorance had contaminated in the human heart, repentance might sweep it, scrape it, and cast it out. It would prepare a clean house of the breast for the Holy Spirit who was about to come upon it, so that he might gladly bring himself in with heavenly goods. One title of these goods is human salvation, with the abolition of former sins sent ahead. This is the cause of repentance, this its work, attending to the business of divine mercy. Whatever benefits a human being is what serves God.

Moreover, the rule of repentance, which we learn once we have come to know the Lord, holds to a fixed form: it must never lay violent hands, so to speak, on good deeds or good thoughts. For God does not hold the rejection of good things as valid, since they are his own. As their author and defender, he must also be their acceptor, and if their acceptor, then also their rewarder. Let human ingratitude see to it, then, if it plans repentance even for good deeds. Let gratitude see to it too, if courting it is an incentive to doing good. Both are earthly and mortal. How small is the gain if you do good to a grateful person, or the loss if to an ungrateful one? A good deed has God as its debtor, just as an evil deed does, because every judge is the rewarder of a case.

But since God the judge presides over justice, which he holds dearest and demands and defends, and since he ordains the whole sum of his discipline toward it, can there be any doubt that in the matter of repentance, as in all our actions, justice must be rendered to God? And this can only be fulfilled if repentance is applied to sins alone. For sin does not deserve to be called anything but an evil deed, and no one sins by doing good. But if he does not sin, why does he seize upon repentance, the private property of sinners? Why does he impose the office of wickedness on his own goodness? So it happens that when something is applied where it should not be, it is neglected where it should be.