God promises to forgive my sin if I confess it to Him.
No mere man is going to get off telling me that that man himself retained any sins of mine that God promised He would forgive if confessed.
God is not subservient to the whims of man.
“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.’ “