I think people will exist eternally...with or without God. I think we were created to exist forever. We will either exist eternally separated from God by sin...or we will exist eternally with God through forgiveness and salvation. I think to be eternally separated from God is hell....and to be eternally in union with Him is eternal life in Heaven. I do think Heaven and hell are real places of eternal existence.
But, if the only thing keeping a person decent is the expectation of a divine reward...or the avoidance of a divine punishment...those seem to be pretty self-centered motivations.
