Confession heals, confession justifies, confession grants pardon of sin, all hope consists in confession; in confession there is a chance for mercy. --St. Isidore of Seville

"It is in pardoning that we are pardoned."

Three conditions are necessary for Penance: contrition, which is sorrow for sin, together with a purpose of amendment; confession of sins without any omission; and satisfaction by means of good works. --St. Thomas Aquinas