Great question!
The after death "reward" could be that if you do X,Y,Z you become a god and are given a planet of your own... where you can basically "design" your own world and can choose to inhabit it.
My basic complaint with Christianity's Heaven is that it's pre-defined, and it sounds more like a hell to me. I don't really care for jewels and gold, and most certainly not all that awful choir singing.
