Me: So the lawbreaking of the forgiven is not punished?
DavidW: No. I don't mean to get personal at all, as I don't like personal and familial references in arguments and debates, so excuse me please: if your son dropped a glass of milk on the floor and then said he's sorry and started to wipe it up -- would you spank him for it? Of course not. "If you who are evil give good gifts to your children..." -- well, you know the rest.
Me: Is God, then, unjust?
DavidW: Yes, essentially. And are you unjust not to spank the son who drops the milk even though he's apologized and started to wipe it up? God is not a slave to his own nature. Above all, he is merciful. One of the Fathers, I can't remember which, said it very well once. We should never pray for God's justice, he said, as God's justice is our condemnation -- we should continually pray and hope for his unjustness.
Me: Does He just ignore the law, broken by the sinner?
DavidW: Yes -- that would be the definition of "forgiven." If a bank forgives your debt are you still obligated to pay them something? If you forgive your neighbor for talking bad to you -- do you still harbor hostility or require that he exact some kind of penance or pay some debt? Of course not.
You've said that the Orthodox don't take sin seriously -- I think the problem is that Calvinists don't take God's mercy and lovingkindness seriously. In fact, you don't take God seriously. He says he forgives -- you say he still requires a debt to be paid; the two statements stand in contradiction. You make God a liar yet again. (source, emph mine)
So apparently God just ignores His holy, righteous law whenever He wants to.
Apparently sinning against God's law is like spilling a glass of milk and then starting to wipe it up.
Apparently the sinner, even though the Bible says numerous times that he is God's enemy, is actually a son.
Apparently God can change His nature when He wants to.
You know who he sounds exactly like? The mostly-secularised N African Muslims with whom I shared the Gospel of grace this summer. I mean exactly like them, no difference, except I couldn't get many of them to admit that God is unjust. They just kind of ignored the contradiction.
See, this is when the substitutionary atonement would come in mighty handy for him, but he just can't bear to admit to himself or anyone else the serious problem here.