An afterlife isn't necessarily defined by religious beliefs.
It seems more often than not that religion has very little to do with God, and very little to do with whether there is an afterlife.
Serious studies have been done on the Near Death Experience. The people who have them often share some interesting similarities in the retelling, like the feeling of leaving one's body, of seeing relatives and friends (oddly enough, all of whom have already passed away - they do not say they encounter anyone still living on the other side during their experience.) Some accurately relate events that they could not have seen from their deathbed after they are resuscitated.
Because of religious upbringing, people who experience NDE's tend to use descriptive metaphors that align with their belief-system.
Except for small children, who experience NDE's and are too young to be indoctrinated into the formalities of religion. Those children tend to describe similar experiences using their limited language skills.
One recurring theme is the "life-review" - but not as an observer like in a movie-theater, but as a direct participant on a hyper-aware level, able to feel everything that everyone else feels as a result of the actions taken in life - even the ripple effects out to people once or twice removed from direct contact (like, killing an enemy, but feeling not only what he felt, but the affects on his wife and children later).
This last part may be what is Final Justice, because if something like that occurs, I could only imagine that someone like a Hitler or a Stalin is just getting started...
