"But one whom you forgive anything, I forgive also; for indeed what I have forgiven, if I have forgiven anything, I did it for your sakes in the presence of Christ."
However, that is not at all what this verse is saying. In context, the Apostle Paul exhorted the Church of Corinth to discipline a man who was living in sin.
Verse eight was a call for them to restore fellowship with that person. Verse nine is the author's reminder of writing to them. Paul is saying that if they forgive someone and say that he is repentant, then he will restore with them as well because he has trust with them. He is telling them to return the favor. He is saying the sinner is repentant. The Corinthian Christians were told to receive him back.
The Roman Catholic dogma of confession to a priest expressly contradicts the teaching of the New Testament. There is one mediator between God and mankind, and His name is Jesus Christ (1 Timothy 2:5-6). We are to approach Him directly for the forgiveness of sin. Only He can reconcile us to a holy God. Thus, the Roman Catholic priest is self-deceived and stopping others from entering into the kingdom of heaven. The concept of an ordained ministerial priesthood is nowhere to be found in the New Testament.
1 John 1:7-9 mentions God thoroughly cleansing believers who confess their sins before Him without any mention of an ordained ministerial priest. That passage of Scripture does not even make a distinction between mortal and venial sins.
The Roman Catholic priest is actually unnecessary because Christ lives forever to make intercession before the Father for those who have placed their trust in Him (Hebrews 7:24-25). His role cannot be transferred to other people. Who does the Roman Catholic priest confess his sins to, another priest? This tradition is simply preposterous. There cannot be an ordained, ministerial priesthood because no more offerings exist for sin (Hebrews 10:17-18).