You should see the movie "Waking Life" if you haven't already. There are many viewpoints based on a central belief: there is more to life and death than what it seems. The movie basically summarizes my "religious" beliefs (because I don't really have a religion) It also has some info about lucid dreaming and astral projecting, which sort of sparked my interest. it's definitley worth it!
I believe that consciousness is something that cannot be destroyed, but is rather channeled through a human body to gain new experiences and things to create. These experiences and stored memories from the "real world" are released in death, forming a highly realistic and controllable world. Heaven and Hell exist based on the things that we as beings see and do on earth. In a way, the physical world is a medium where all consciousness (whether it's on earth or not) can interact and add to consciousness as a whole.