On the Christian front here is my take (which is of course, considered blasphemy

) Just like you don't tell your kids EVERYTHING, why do we assume God tells us everything?
When the bible mentions heaven./hell, it always seems to me that Hell is separation from God. And isn't that what we are on Earth? Separated from God, subject to temptation, prone to illness, pain, sadness, etc?
What if...just maybe...when we die God says, "Honey, I love you SO much, but you didn't get it right." And what if...instead of hellfire and pitchforks, God sent us back to Earth to get it all figured out so that we CAN be with him?
For as much as we like to project God as forgiving, we sure do get a bee in our bonnets about what happens to people once they die. Fact is, we Don't know.
I don't know. Maybe it is something like that, maybe it isn't.