the way I see it is this... even if something dramatic were to happen where most of us perished.. life your life for the better, and it will benefit you no matter what. I'm buddhist though so I believe that the better I live in this life it will benefit my next life and so on... just not worth it to throw your whole life away just because you think its the end... because if buddhism is correct, then your next life will be way better, or you could even transcend to another level of existence . . . .
but yeah I know many people wont be on the same side as me on this one... it requires some form of faith but the fact is I saw this guy who went into a hospital for trauma of some sort, had his eyes covered completely, and was watching from OUTSIDE his body, what the surgeon was doing, and a particular stretch unique ONLY to this surgeon that he was able to identify upon survival...
this singular event... is enough proof for me to believe in past lives, future lives, and karma to the fullest extent the buddhists believe in...