I was doing a bible study with a girl today on 1 Peter 1, and we were blowing out about how much we forget about heaven (and our inheritance there that can never "perish, spoil or fade"), how far off it can seem and how we get so tangled up in our lives here.
Our little boy Xavier (4 1/2) talks about heaven a fair bit at the moment, and for him its a concrete thing that *will* come, maybe in a couple of weeks, maybe tomorrow. The questions he asks are concrete, like "how much chocolate will there be in heaven?" and "what do you think Jesus will look like when we meet him?" and "what will Jesus say to me when I get there?", to which I give frustratingly abstract answers. Although he's struggling not to sin, he lives with the certainty that heaven is in his future, even more sure than the holiday we've planned for a few weeks time or the baby being born.
I'm going to model my thinking about the certainty of heaven and my trust in God's plans for this world and eternity on Xavi....he's understands it much more biblically than me.