“When he celebrates the sacrament of Penance, the priest is fulfilling the ministry of the Good Shepherd who seeks the lost sheep, of the Good Samaritan who binds up wounds, of the Father who awaits the prodigal son and welcomes him on his return, and of the just and impartial judge whose judgment is both just and merciful. The priest is the sign and the instrument of God's merciful love for the sinner.” (Catechism of the Catholic Church, 1465)
The Sacrament of Penance is the sacrament of spiritual healing. Reconciliation involves contrition, confession to a priest, absolution by the priest, and penance. After making an examination of conscience, the penitent confesses his/her sins to the priest, who is the minister of Christ’s mercy. The intent of this sacrament is to provide healing for the soul as well as to regain the grace of God, lost by sin.
The US Conference of Catholic Bishops has a terrific website with a lot of information related to the Sacrament of Penance and Reconciliation. Click Here to go to it.
Jesus said to them again,
"Peace be with you. As the Father has sent me, so I send you."
And when he had said this, he breathed on them and said to them,
"Receive the holy Spirit.
Whose sins you forgive are forgiven them, and whose sins you retain are retained."