“The people of God accomplish and perfect this continual repentance in many different ways. They share in the sufferings of Christ by enduring its own difficulties, carry out works of mercy and charity, and adopt ever more fully the outlook of the Gospel message. Thus, the people of God become in the world a sign of conversion to God. All this the Church expresses in its life and celebrates in the liturgy when the faithful confess that they are sinners and ask pardon of God and of their brothers and sisters. This happens in penitential services, in the proclamation of the word of God, in prayer, and in the penitential aspects of the eucharistic celebration.”
In the sacrament of penance the faithful “obtain from the mercy of God pardon for their sins against him; at the same time they are reconciled with the Church which they wounded by their sins and which works for their conversion by charity, example and prayer.”
(From the Rite of Penance, Introduction, No. 4)