I am afraid because what if God/concept of heaven does not exist, then death would just be a big void of non-existence. No consciousness, no memory, nothing. That's like floating in dark space with no idea who you are or your purpose there.
Even after I pass away, I want to see how humanity progresses, or the mysteries of nature and life that are yet to be solved. Or how and when
the world will end (
vote for TTWE 
). I want some sort of continuation/connection with the world even if I'm not physically there.