Tim Staples – Catholic Answers Article –
The Catholic Church acknowledges what Scripture unequivocally declares: it is God who forgives our sins. But that is not the end of the story.
If a man lies carnally with a woman… they shall not be put to death… But he shall bring a guilt offering for himself to the Lord… And the priest shall make atonement for him with the ram of the guilt offering before the Lord for his sin which he has committed; and the sin which he has committed shall be forgiven him.
Leviticus 19:20-22
Apparently, a priest being used as God’s instrument of forgiveness did not somehow take away from the fact that it was God who did the forgiving. God was the first cause of the forgiveness; the priest was the secondary, or instrumental cause.
Just as God empowered his priests to be instruments of forgiveness in the Old Testament, the God/man Jesus Christ delegated authority to his New Testament ministers to act as mediators of reconciliation as well.
Jesus said to them again, “Peace be with you. As the Father has sent me, even so I send you.” And when he had said this, he breathed on them, and said to them, “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
Having been raised from the dead, our Lord was here commissioning his apostles to carry on with his work just before he was to ascend to heaven. “As the Father has sent me, even so I send you.” What did the Father send Jesus to do? All Christians agree he sent Christ to be the one true mediator between God and men. As such, Christ was to infallibly proclaim the Gospel (cf. Luke 4:16-21), reign supreme as King of kings and Lord of lords (cf. Rev. 19:16); and especially, he was to redeem the world through the forgiveness of sins (cf. I Peter 2:21-25, Mark 2:5-10).
The New Testament makes very clear that Christ sent the apostles and their successors to carry on this same mission. To proclaim the gospel with the authority of Christ (cf. Matthew 28:18-20), to govern the Church in His stead (cf. Luke 22:29-30), and to sanctify her through the sacraments, especially the Eucharist (cf. John 6:54, I Cor. 11:24-29) and for our purpose here, Confession.