You are choosing to focus on the specifics of one religion and one belief system. Not all religions or belief systems include burning in hell or accepting Christ as a savior. Not all belief systems are limited to one God either.

I think it is important to separate organized religions from beliefs when discussing what would happen if the existence of a supreme being were actually proven.

OK, pick one and we'll talk. But remember, being "proven" has some ground rules, ground rules which would immediately invalidate certain religions.

Hint: I'd stay away from Islam - all someone has to do is project a picture of what he/she thinks the Islam God looks like, and they get death threats.