Do not overlook the preceding words Wag.. They were being shown that their spiritual lives and ministry were under the authority of God and not their own.
Can you think of one instance where the apostles forgave someone's sins or with held forgiveness?So they must not have understood it as literally as many take it,
What we did see was them exercise ecclesiastical authority to excommunicate unrepentant sinners ..
It was 1200 before the church instituted confession to a priest.. so it seems it was not as clear as you want to present it..
Jesus said to pray like this ".....Forgive us our trespasses as we forgive those that trespass against us.. ..Not as peter forgives us :)
Thanks for the ping.