the past,present and future all exist at the same time
after you die,the mind sees what it expects to see based on the thoughts and experiences of the person experiencing the "vision" , like a self-induced dream
you've already seen your own heaven and hell
after all,you do have dreams,don't you?
you have already experienced your own death,millions of times
now that you know this information,you must use it
you must start practicing lucid dreaming,you must learn how to control your dreams
it will be too late the moment you realize you can't wake up