CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 1478–1481

1478 An indulgence is obtained through the Church who, by virtue of the power of binding and loosing granted her by Christ Jesus, intervenes in favor of individual Christians and opens for them the treasury of the merits of Christ and the saints to obtain from the Father of mercies the remission of the temporal punishments due for their sins. Thus the Church does not want simply to come to the aid of these Christians, but also to spur them to works of devotion, penance, and charity.
1479 Since the faithful departed now being purified are also members of the same communion of saints, one way we can help them is to obtain indulgences for them, so that the temporal punishments due for their sins may be remitted.
1480 Like all the sacraments, Penance is a liturgical action. The elements of the celebration are ordinarily these: a greeting and blessing from the priest, reading the word of God to illuminate the conscience and elicit contrition, and an exhortation to repentance; the confession, which acknowledges sins and makes them known to the priest; the imposition and acceptance of a penance; the priest's absolution; a prayer of thanksgiving and praise and dismissal with the blessing of the priest.
1481 The Byzantine Liturgy recognizes several formulas of absolution, in the form of invocation, which admirably express the mystery of forgiveness: "May the same God, who through the Prophet Nathan forgave David when he confessed his sins, who forgave Peter when he wept bitterly, the prostitute when she washed his feet with her tears, the publican, and the prodigal son, through me, a sinner, forgive you both in this life and in the next and enable you to appear before his awe-inspiring tribunal without condemnation, he who is blessed for ever and ever. Amen."