God's Word promises "If we confess our sins, He is faithful and just to
forgive us and cleanse us from all unrighteousness" (1 John 1:9).
Jesus, giving His disciples the authority to forgive sin, said: "If you
forgive the sins of any, they are forgiven them; if you retain the sins
of any, they are retained" (John 20:23; c.f. Matt. 16:19, 18:17-19).

Priests are only the visible instrument of God's mercy at the
performance of the Mystery, which is performed invisibly through
them by God Himself. It is God (the Holy Triune) who forgives our sins.
Confession