In Roman Catholicism, penance is a means by which all sins committed after baptism are removed. The means are assigned by a priest and usually consist of special prayers or deeds performed by the sinner. It is considered a sacrament, a means of grace.

• “As a means of regaining grace and justice, penance was at all times necessary for those who had defiled their souls with any mortal sin,” (Catholic Encyclopedia, “Penance,” newadvent.org/cathen/11618c.htm, also The Council of Trent, Session XIV, c. i.)
• “The effect of this sacrament [penance] is deliverance from sin,” (Catholic Encyclopedia, “Penance,” newadvent.org/cathen/11618c.htm).
• “It is through the sacrament of Penance that the baptized can be reconciled with God and with the Church . .  . this sacrament of Penance is necessary for salvation for those who have fallen after Baptism,” (Catechism of the Catholic Church, par. 980).
• “Christ instituted the sacrament of Penance for all sinful members of his Church: above all for those who, since Baptism, have fallen into grave sin, and have thus lost their baptismal grace and wounded ecclesial communion. It is to them that the sacrament of Penance offers a new possibility to convert and to recover the grace of justification. The Fathers of the Church present this sacrament as “the second plank [of salvation] after the shipwreck which is the loss of grace,” (CCC 1446).