YOU HAVE MORE THAN YOU KNOW.
But seriously, why would you want to "imagine there's no heaven"?
I can get…
"Evidence and rational thought suggests there is no heaven. But if my reasoning has erred that would be amazing."
Or:
"Heaven sounds like it sucks, sitting around in white robes and being love-dovey. I wish it were more enthralling."
But "imagine there's no heaven" makes no sense.
Just sayin….