Hope is such a comforting thing, I think its fundamental to our health as well as our ability to be happy. Belief in what I hope for is a different thing entirely and can get me into trouble when I am not paying close attention. In the end though, what I believe about the future and the past simply colors the present but doesn't change it.
SouisLight: I suspect that people hang on when they are miserable not because they hope for better experience in this life but because deep down they know that what they believe about existence after death is likely to be incorrect. So, the situation turns into "better off with the devil you know as opposed to the one one you don't," which is basically fear. Also, at least for me, it seems that total oblivion would extenguish all possibilities permanently and I personally would not like that situation. I would rather be miserable and have the possibility of becoming even more miserable than having nothing whatsoever.