Jollyblogger weighs in on an interesting debate between John Piper and Phil Gons over whether there's regret over sin in heaven. David sides with Gons. I'm going to have to go with Piper on this one. As I said in my comment there,
So does God literally forget our sin? I know the verse that says he'll forget our sins, but is that literally true? Does God cease to be omniscient in the new creation? I doubt it. So if God can remember our sin and still be in perfect restoration of all good, then why can't the same be true of us?
I remember loving Miroslav Volf's Exclusion and Embrace for most of the first few chapters. The first thing that really threw me was his suggestion that we wouldn't remember anything bad from our earthly lives in the new creation. Why would God deceive us? Isn't only the truth in God and not lies? Even people like me who think lying can be ok in extreme circumstances in a fallen world don't think lying is ok in a perfect, restored community, and yet this is a suggestion of exactly that. I think I'm with Piper on this. [Links added]
The Bible speaks of God regretting certain things he does. One way to take this is in the open theistic way, wherein God couldn't manage to figure out what was going to happen once he did something, and then when it happened he wished he'd done otherwise than the bone-headed move he'd made, but it was too late to turn back. Another is to take all talk of regret as anthropomorphisms, and since God has no emotions at all it's just describing the way God behaves. God does things that seem to us as if God has regret. It's consistent with the way the Bible speaks of God's plans just to say that God does regret but not in a way that involves wishing he'd done otherwise.
It's actually quite easy to find cases where that's true. If there really are only two options, and each one involves something bad, then I might choose one simply because the combination of goods and bads in that option is better than the combination in the other option. That's too simplistic to compare to the decision-making that goes on in selecting which world to create, but most plausible answers to the problem of evil involve something like this. There are bad things in the universe. If you think about them in isolation from everything else, they are bad, and they deserve regret. There's something unfortunate about them. Yet when seen in the light of the whole, they occupy a place in tGod's overall plan of providence that means they're contributing toward the perfection of God's work in overseeing how creation has developed and is moving toward its culmination. At the micro-level, they are unfortunate and deserve regret. At the macro-level, they are perfect and deserve joy.
My suggestion is that this is how God sees evil. If God is temporal, this is how God sees evil now, but it's also how he'll see it once everything is restored. If he's atemporal, how he sees things is always how he sees things. Either way, it doesn't seem problematic for God to regret if it's regret about things in their intrinsic nature, which is entirely true in terms of the micro-level. Yet such regret is bad if it's absent from the macro-level joy in all that is good in God's overall plan of providence. So there's no reason to think human beings, once much more (perhaps fully aware) of the fullness of that plan, won't feel regret. I think there's every reason to think we'll have the same kind of regret I take the Bible to be speaking of God having.