Christ destroyed what was diabolical, took upon Himself what was human, and conferred on the Church what was divine. So all that belonged to the Bride was shared by the Bridegroom, and He Who had done no wrong and on Whose Lips was found no deceit could say: Have mercy on Me, O Lord, for I am weak (Ps 6, 3). Thus, sharing as He did in the Bride’s weakness, the Bridegroom made her cries of distress His own, and gave His Bride all that was His. Therefore, the Church too has the prerogative of receiving the confession of sin and the power to forgive sin, which is the reason for the command: Go, show yourself to the priest (Lc 5, 14).
The Church is incapable of forgiving any sin without Christ, and Christ is unwilling to forgive any sin without the Church. The Church cannot forgive the sin of one who has not repented, who has not been touched by Christ; Christ will not forgive the sin of one who despises the Church. What God has joined together, man must not separate. This is a great mystery, but I understand it as referring to Christ and the Church.
Do not destroy the whole Christ by separating Head from Body, for Christ is not complete without the Church, nor is the Church complete without Christ. The whole and complete Christ is Head and Body. This is why He said: No man has ascended into heaven but He that descended from heaven, the Son of Man Who is in heaven (Io 3, 13). He is the only Man Who can forgive sin.
~ Isaac of Stella ~