Imagine no religion at all, that humans believed in nothing but humankind and no existence after death.
What would life be like?
I read an observation a while back that said something like this:
For unbelievers, this is the closest they'll ever get to heaven.
But for believers in Christ, this is the closest they'll ever get to hell.
I now think of this every time I go through something, whether good or bad.
All the joys we know of this life, as wonderful or as limited as they might seem, are the greatest things any unbeliever will experience. We believers, however, know there is much, much more ahead. So much more, and so much better than we could ever imagine.
But at the same time, all the horrible, tragic, gut-wrenching things of this life -- and we are seeing everyday just how bad it can get -- these are the closest experiences we believers will ever get to hell, which God has promised to save us from.
I don't even want to imagine what an existence without God's presence would be like -- but this is exactly what will happen to unbelievers in the end -- they will be cast from God's presence forever, with not even a glimpse of His goodness left, as we still have on this earth.
I read another musing once that maybe this is part of why God allowed sin to enter the world in the first place -- He wanted to give humans a chance to see and experience what life could be like if they decided to chose Him -- or not.