I guess because various people believe different thing will happen to them when their life ends. The question is- which of those options (on what happens when life ends) is truly what's going to happen. Surely, if Bible is true you want to live such life so you are not ending up in hell, if Quran is true you do whatever it says to maximise the outcome, same for Hindu, Budha, and of course Atheism. I study this to have strong grounding on how to live, and there is scientiffic method to do this, though it requires time and effort.