We as humans are terrified of dying,
We create an imaginary world where we defy death, where we don't die,
Yes our bodies may not exist anymore but we still live, because we as humans will never believe that we can die. We create "religions" we have a "hope" that we can live forever. But why? Why can't we just accept that we will be buried in a 6ft hole in the ground and nothing else will happen? Because it's a human survival instinct, our brains tell us "what ever the cost you must not die" so when we do really die we believe that we are still alive. Other people also  think that we are in "heaven". This I find fascinating in a phycological and theological aspect due to the fact that not only are you able to perceive the religious aspects behind death, but the phycological toll that a person grieving experiences.
When you ask a person of a religious belief what death is to them, 9/10 of the people asked, responded with words very similar to each other. These descriptions describe a sort of afterlife "the denial of death" these questions were asked to many people with different cultural and religious beliefs. But to define death is like defining religion itself.