Penance is the sacrament by which sins committed after Baptism are forgiven through the absolution of the priest.
Penance prompts the sinner to detest his sins, and incites him to offer satisfaction for them, and to amend his life in the future.
1. Penance has the three essentials of a sacrament.
(a) It is a sensible sign; i.e., the words of absolution and the act of confession.
Our Lord promised to give Peter the power to forgive sins, saying to him, “And whatever thou shalt bind on earth shall be bound in heaven, and whatever thou shalt loose on earth shall be loosed in heaven” (Matthew 16:19). Christ later made the same promise to the other Apostles, saying, “Amen, I say to you whatever you bind on earth shall be bound also in heaven; and whatever you loose on earth shall be loosed also in heaven” (Matthew 18:18).
(b) It was instituted by Jesus Christ on the First Easter Sunday night.
On the first Easter Sunday night, Our Lord fulfilled His promise to give His Apostles the power to forgive sins. Jesus appeared to His Apostles and said: “Peace be to you. As the Father has sent me, I also send you.” When He had said this, He breathed upon them and said to them: “Receive the Holy Spirit; whose sins you shall forgive, they are forgiven them; and whose sins you shall retain, they are retained” (John 20:21-23).
(c) It confers grace. It is the way by which after Baptism sanctifying grace is restored to the penitent who has committed mortal sin.
2. On the part of the penitent, the sacrament of Penance includes three distinct acts:
(a) contrition or sorrow for his sins;
(b) confession or telling them to the priest; and
(c) satisfaction or performance of the penance imposed by the priest.
A penitent is absolved IF he confesses his sins with sorrow, makes a resolution to atone for them, and promises to amend his life.
3. The practice of confession and sacramental remission of sin has been continuous in the Church from the beginning, though the manner of administering this sacrament has evolved through the centuries.
In the writings of the Fathers and Doctors of the Church, in the very first centuries of the Christian era, the faithful are often advised and exhorted to confess their sins. St. Augustine says, “It is not enough that one acknowledge his sins to God, from whom nothing is hidden; he must also confess them to a priest, God’s representative.”
St. John said in encouragement: “My dear children, these things I write to you in order that you may not sin. But if anyone sins, we have an advocate with the Father, Jesus Christ the just” (1 John 2:1).