From Pope St. John Paul II’s Apostolic Exhortation Reconciliatio et Pænitentia (1984):
From the revelation of the value of this ministry and power to forgive sins, conferred by Christ on the apostles and their successors, there developed in the church an awareness of the sign of forgiveness, conferred through the sacrament of penance. It is the certainty that the Lord Jesus himself instituted and entrusted to the church—as a gift of his goodness and loving kindness172 to be offered to all—a special sacrament for the forgiveness of sins committed after baptism.
The practice of this sacrament, as regards its celebration and form, has undergone a long process of development as is attested to by the most ancient sacramentaries, the documents of councils and episcopal synods, the preaching of the fathers and the teaching of the doctors of the church. But with regard to the substance of the sacrament there has always remained firm and unchanged in the consciousness of the church the certainty that, by the will of Christ, forgiveness is offered to each individual by means of sacramental absolution given by the ministers of penance. It is a certainty reaffirmed with particular vigor both by the Council of Trent173 and by the Second Vatican Council: “Those who approach the sacrament of penance obtain pardon from God’s mercy for the offenses committed against him, and are, at the same time, reconciled with the church which they have wounded by their sins and which by charity, by example and by prayer works for their conversion.”174 And as an essential element of faith concerning the value and purpose of penance it must be reaffirmed that our savior Jesus Christ instituted in his church the sacrament of penance so that the faithful who have fallen into sin after baptism might receive grace and be reconciled with God.175
The church’s faith in this sacrament involves certain other fundamental truths which cannot be disregarded. The sacramental rite of penance, in its evolution and variation of actual forms, has always preserved and highlighted these truths. When it recommended a reform of this rite, the Second Vatican Council intended to ensure that it would express these truths even more clearly,176 and this has come about with the new Rite of Penance.177 For the latter has made its own the whole of the teaching brought together by the Council of Trent, transferring it from its particular historical context (that of a resolute effort to clarify doctrine in the face of the serious deviations from the church’s genuine teaching), in order to translate it faithfully into terms more in keeping with the context of our own time.
172 Cf Ti 3:4.
173 Cf Council of Trent, Session XIV De Sacramento Pœnitentiæ, Chap. 1 and Canon 1: Conciliorum Œcumenicorum Decreta, 703f, 711 (Denzinger, Heinrich, and Adolf Schönmetzer, Enchiridion symbolorum definitionum et declarationum de rebus fidei et morum [DS] 1668-1670, 1701).
174 Lumen Gentium, 11.
175 Cf Council of Trent, Session XIV, De Sacramento Pœnitentiæ, Chap. l and Canon 1: Conciliorum Œcumenicorum Decreta, ed. cit., 703f, 711 (DS 1668-1670, 1701).
176 Cf Constitution on the Sacred Liturgy Sacrosanctum Concilium, 72.
177 Cf Rituale Romanum ex Decreto Sacrosancti Conalii Œcumenici Vaticani II Instauratum, Auctoritate Pauli VI Promulgatum: Ordo Pænitentiæ, Vatican Polyglot Press, 1974.
— Reconciliatio et Pænitentia 30