SACRAMENT OF PENANCE
The sacrament that, by means of certain acts of the penitent and by the absolution of a qualified priest, remits sins committed after baptism. As defined by the Catholic Church, it is "truly and properly a sacrament, instituted by Christ our Lord, for reconciling the faithful to God as often as they fall into sin after baptism" (Denzinger 1701). The required acts of the penitent are contrition, confession, and the willingness to make satisfaction. These acts are called the matter of the sacrament. The priest's absolution is the form.
The sacrament of penance was instituted by Christ on Easter Sunday night, when he told the Apostles, "Receive the Holy Spirit. For those whose sins you forgive, they are forgiven; for those whose sins you retain, they are retained" (John 20:22-23). The Catholic Church interprets these words to imply that Christ conferred on the Apostles and their successors not merely the right to declare that a person's sins are forgiven but also the power of forgiving in Christ's name those who are judged worthy of remission and of withholding absolution for those who are not disposed to be absolved.