On the Lord's Prayer 22

After this we also pray for our sins, saying: "And forgive us our debts, as we also forgive our debtors." After the support of food, pardon for sin is asked, so that he who is fed by God may live in God, and provision may be made not only for the present and temporal life but for the eternal, to which one can come if sins are forgiven, which the Lord calls debts, as he says in his gospel: "I forgave you all the debt, because you asked me." How necessarily, how providently and wholesomely we are reminded that we are sinners, who are compelled to ask for our sins, so that, while pardon is sought from God, the soul may remember its own conscience! Lest anyone should be pleased with himself as if innocent, and by exalting himself perish the more, he is instructed and taught that he sins daily, since he is commanded to pray daily for his sins. So finally John too warns in his letter, saying: "If we say that we have no sin, we deceive ourselves, and the truth is not in us. But if we confess our sins, the Lord is faithful and just to forgive us our sins." In his letter he has included both: that we ought to pray for our sins, and that we obtain pardon when we pray. Therefore he called the Lord faithful to forgive sins, keeping faith with his promise; because he who taught us to pray for our debts and sins has promised fatherly mercy and the pardon that will follow.