John 20:23

Whosesoever sins ye forgive

(αν τινων αφητε τας αμαρτιας). "If the sins of any ye forgive" (αφητε, second aorist active subjunctive with αν in the sense of εαν), a condition of the third class. Precisely so with "retain" (κρατητε, present active subjunctive of κρατεω).They are forgiven

(αφεωντα). Perfect passive indicative of αφιημ, Doric perfect for αφειντα.Are retained

(κεκρατηντα). Perfect passive indicative of κρατεω. The power to forgive sin belongs only to God, but Jesus claimed to have this power and right (Mark 2:5-7). What he commits to the disciples and to us is the power and privilege of giving assurance of the forgiveness of sins by God by correctly announcing the terms of forgiveness. There is no proof that he actually transferred to the apostles or their successors the power in and of themselves to forgive sins. In Matthew 16:19; Matthew 18:18 we have a similar use of the rabbinical metaphor of binding and loosing by proclaiming and teaching. Jesus put into the hands of Peter and of all believers the keys of the Kingdom which we should use to open the door for those who wish to enter. This glorious promise applies to all believers who will tell the story of Christ's love for men.