This sacrament is rooted in the mission God gave to Christ in his capacity as the Son of man on earth to go and forgive sins (cf. Matt. 9:6). Thus, the crowds who witnessed this power "glorified God, who had given such authority to men" (Matt. 9:8).
After his resurrection, Jesus passed on his mission to forgive sins to his ministers, telling them, "As the Father has sent me, even so I send you... Receive the Holy Spirit. If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained" (John 20:21-23).
"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 lost their baptismal grace and wounded ecclesial communion. It is to them 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.'"
Catechism of the Catholic Church no. 1447




