To return to communion with God after having lost it through sin is a process born of the grace of God who is rich in mercy and solicitous for the salvation of men. One must ask for this precious gift for oneself and for others.
-Catechism of the Catholic Church 1489
Those who approach the sacrament of Penance obtain pardon from God's mercy for the offense committed against him, and are, at the same time, reconciled with the Chruch which they have wounded by their sins and which by charity, by example and by prayer labors for their conversion.