Catholics aren't supposed to read their bibles, they'll go crazy. I think that to someone who has been brought up in the catholic system, you could argue that point, especially in light of the fact that catholics aren't supposed to interpret scripture on their own anyway. But I think that would be a very weak argument.
This is one of those verses that doesn't get a lot of attention from preachers, so I'm looking at this for the first time myself right now. I wouldn't like to think that I was responsible for remitting or retaining another man's sin, but lets see what we can make of this.
First, it doesn't say anything about how the remitting is to be done. Confession is a wonderful thing for obtaining forgiveness from the Lord, but we do not have to go to a man for that.
Psalms 32:5 I acknowledged my sin unto thee, and mine iniquity have I not hid. I said, I will confess my transgressions unto the LORD; and thou forgavest the iniquity of my sin. Selah.
The scribes may have missed the mark with the identity of Christ, but they did have some knowledge of the things of God:
Mark 2:7 Why doth this man thus speak blasphemies? who can forgive sins but God only?
I don't think this is saying that the apostles had the power to grant or deny the forgiveness of sins in an absolute sense. So the question remains, just what is the Lord talking about? (seems to be a common question among His followers, too.)
Mathew Henry seems to think that due to the special indwelling of the Spirit that Christ imparted to them, that they did have the authority to pronounce a mans sins to be forgiven or to bind their sins to them, by virtue of the discernment of the Holy Ghost. He cites the account of Annanias and Saphira (he says they were struck down by Peter) and Paul blinding Elymas. Basically being able to judge rightly the hearts of men, by the Holy Ghost. I would not take this to mean the Apostles decided who was saved or not, but rather this would deal with practical sanctification and how unconfessed, unrepentant sin in a believer's life will affect fellowship and reward.
It could also be referring to forgiving the sins of others toward us, as the Lord commands us to do of our brothers, if they repent.
Luke 17:3-4
3 Take heed to yourselves: If thy brother trespass against thee, rebuke him; and if he repent, forgive him.
4 And if he trespass against thee seven times in a day, and seven times in a day turn again to thee, saying, I repent; thou shalt forgive him.
The Lord gives us the example of forgiving our enemies as well, which we should do if we would be like Him, our example:
Luke 23:34
34 Then said Jesus, Father, forgive them; for they know not what they do. And they parted his raiment, and cast lots.
But I think possibly that if someone sins against us, and will not repent of it, we are not under obligation to forgive them. Take for instance Alexander the coppersmith:
2 Timothy 4:14-15
14 Alexander the coppersmith did me much evil: the Lord reward him according to his works:
15 Of whom be thou ware also; for he hath greatly withstood our words.
That doesn't sound like forgiveness, particularly, although I would think that prayer for such a man would be in order. We are also told to deal with brethren who walk disorderly, for instance the fornicator in Corinth, in similar fashion:
1 Corinthians 5:5
5 To deliver such a one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus.
But for one who is repentant, I think this would apply:
Galatians 6:1
1 Brethren, if a man be overtaken in a fault, ye which are spiritual, restore such a one in the spirit of meekness; considering thyself, lest thou also be tempted.
So delivering one to Satan could be retaining his sins, while restoring him could be to remit...
Also, we could just be talking about going out, preaching the Gospel, and shaking the dust off for those who will not recieve us. What do you think?