The unsinnable forgive?

I was wondering, what do Arminians and Calvinists (and the rest) make of the following. The relevant section is bold, but I included the rest for context:

I seem to recall that someone who was arguing for free will had claimed that when Christ died all sins were forgiven, therefore the only sin possible now is the sin of unbelief. I was unable to find that post, so if I am in error, feel free to correct me. But if I remember it right, John 20:23 presents something of a problem for that view, doesn't it?

That is, it creates a paradox from the perspective of free will, but not necessarily from the perspective of predestination. It is possible that the text actually means, "If you forgive anyone his sins, it is because they were already forgiven in heaven, but if you don't, it's because they weren't forgiven in heaven." One could still argue that the only way to get to hell now is to commit the sin of unbelief, since the forgiveness from the apostles was only confirming an already done deal. I honestly do not know if that is the meaning here (and I'm tempted to say it doesn't mean that), but the grammar would support that interpretation. But if that interpretation is correct, then it supports predestination, not free will.

So I'd be interested in hearing views from either or both sides.

By the way, does John 20:23 also imply limited atonement?

(Edited to add the last question.)

[ December 04, 2002, 11:58 PM: Message edited by: npetreley ]