Christ forgives sin though His Bride the Church
From a sermon by Blessed Isaac of Stella, abbot
Blessed Isaac of Stella was born 1100 and died in 1169.
He was a French monk, philosopher, theologian, and writer of the 12th century
The prerogative of receiving the confession of sin and the power to forgive sin are two things that belong properly to God alone. We must confess our sins to Him and look to Him for forgiveness. Since only He has the power to forgive sins, it is to Him that we must make our confession.
But when the Almighty, the Most High, wedded a bride who was weak and of low estate, He made that maid-servant a queen. He took her from her place behind Him, at His feet, and enthroned her at His side. She had been born from His side, and therefore He betrothed her to Himself. And as all that belongs to the Father belongs also to the Son because by nature they are one, so also the bridegroom gave all He had to the bride and He shared in all that was hers. He made her one both with Himself and with the Father. Praying for His bride, the Son said to the Father: I want them to be one with us, even as you and I are one.
And so Jesus, the bridegroom is one with the Father and one with His bride the Church. Whatever Jesus found in His Bride harmful to her own nature He took from her and nailed to His cross when He bore her sins and destroyed them on the tree. He received from her and clothed Himself in what was hers by nature; namely, a human nature and body. And in turn gave to His bride the Church what belonged to Him as God. He destroyed what was sinful, took to Himself what was human, and conferred on her what was divine. . . . Therefore, she 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.
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. As Saint Paul says; 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 the head from the body, for Christ as the Head, is not complete without the Church, nor is the Church as the Body, complete without Christ. The whole and complete Christ is both head and body.