A very good question indeed, good sir Bork.
One that I have been wrestling withpersonally, I was struck with the overwhelming sense that this message I believed in was based around a seeming injustice. Why don't I have to pay for the wrong I do? I asked..
I think justice works itself out though, through the laws that are in place by God. Repentance is what God wants, life change, transformation. He want's us to get beyond the point where we suff up. Knowing that I am forgiven by God because of Jesus doesn't make me feel pure and clean after I commit a sin. I'd say that understanding the price that was paid makes me more aware of the seriousness of sin and guilty when I commit a sin. I think that this guilt is part of paying for sin. I know many people who sin all day long and don't feel bad, but I KNOW when I sin. A conviction that is from the holy spirit, and neccessary in promoting repentance(life change).
I also believe that justice will be sorted out in heaven, mainly because the bible says so and I trust it. I think we will be confronted with our sins in heaven, but not seperated from God. Not everyone is the same rank(for want of a better word) in heaven. Jesus speaks of "causing one of these little one's to sin, " he says "it is better for that man to throw himself into the ocean with a millstone round his neck than face God". Not quoted straight from the bible, just memory... My point is he doesn't go easy on anyone's sin, and the sin you spoke of he gave special mention. He is repulsed by it as you are.