The Enchiridion

Now even penance itself, when by the law of the Church there is sufficient reason for its being gone through, is frequently evaded through infirmity; for shame is the fear of losing pleasure when the good opinion of men gives more pleasure than the righteousness which leads a man to humble himself in penitence. Wherefore the mercy of God is necessary not only when a man repents, but even to lead him to repent. How else explain what the apostle says of certain persons: “if God perhaps will give them repentance”? And before Peter wept bitterly, we are told by the evangelist, “The Lord turned, and looked upon him.”