Why does someone have to die if he sees the face of God? A few years ago I would think that our sinful physical body could not bear the presence of a holy God, as a vampire cannot stand sunlight, and we would be destroyed. But recently I've been thinking: What if God is so pure, so perfect, so beautiful etc. that if we could see Him just once, we would be so attracted to Him, that we couldn't bear living a second without him any longer. -- István Gerencsér

Interesting perspective! (And I've always liked the vampire illustration.) Not that I think the Bible commends suicide in order to be with the Lord. (None of the seven suicides in scripture occurs for this reason, and given that the body is a precious temple of the Holy Spirit, we must not destroy it.)

Yet I think you are on to something -- related to another question: Will we be able to sin in heaven? To which I might reply, "Yes, but we would never want to." That is, in God's presence it would be unthinkable to abuse our free will to reject our Lord and Savior.

But back to your point, the incompatibility of sin and the presence of God (Hab 1:13). The fundamental issue is that we are unclean. His holiness would consume us. But there’s also a fellowship issue. My friend David Bercot uses an apt analogy: If you'd been sprayed by a skunk, would you have close fellowship with your friend? Surely not. You'd need to become clean first. So it is when we enter the presence of God. We must be holy (Heb 12:14). This is not the holiness of Christ (somehow or other "imputed" to us), but our personal holiness. Not only must we be washed by Christ (Titus 3:5), but we must be serious about staying clean, from the time we become Christians onward.

By the blood of Christ that can happen. We can stay clean (1 John 1:6-2:6). And we’d better stay clean, living a holy life! For the presence of God is for those who choose his presence -- which means choosing to obey his will, and to cooperate fully with the Christ who died for our sins.