"Behold, now is the appointed time, in which you must confess your sins to God, and to the priest, and by prayer and by fasting, by tears and almsgiving, wipe them away. Why should a sinner be ashamed to make known his sins, since they are already known and manifest to God, and to His angels, and even to the blessed in heaven? Confession delivers the soul from death. Confession opens the door to heaven. Confession brings us hope of salvation. Because of this the Scripture says: First tell thy iniquities, that you may be justified (Is. xliii, 26). Here we are shown that the man will not be saved who, during his life, does not confess his sins. Neither will that confession deliver you which is made without true repentance. For true repentance is grief of heart and sorrow of soul because of the evils a man has committed. True repentance causes us to grieve over our offenses, and to grieve over them with the firm intention of never committing them again."
St. Ambrose, Bishop and Doctor