It's not the world that passes by, you do.

There must be something more than just existing. Every human being must have felt this at a given point in his life. I myself have asked it for so many times and the answer would just boil down to a single thought that 'we are not human beings having a spiritual experience but we are spiritual beings having a human experience'.
Have you been to college? You take a subject which is a prerequisite for another. I think life is like that. Everything you do is a preparation for yet another life of (whatever you wish it would be). I believe that after this earthly experience, life is much better if and only if you do good.
Human experience is a prerequisite of something that is eternal. Everything we do is free to our own will. We are liberated. We make choices. So choose what you believe is for your own fate. Our lives, we make it.