Assuming that Heaven can be experienced fully by the five senses and isn't just some elated level of "existence", it must be a state of absolute contentment and happiness. Many describe heaven as a place of eternal and absolute beauty but that wouldn't seem to be the case anymore - the ever-so-unfalsifiable Bible being retconned several times.
Given that addiction to chocolate isn't a sin, a Heaven-bound person who's addicted to chocolate would experience Heaven as a place filled with his vice. But since not everyone likes chocolate, there wouldn't be a single objective experience of this so-called Heaven. Other heavens would include whatever the Heaven-bound person likes.
But here's an extreme example. Suppose there is a Believer Girl A and an Atheist Guy B who love each other despite their beliefs. When they died, the Guy is sent to hell while the Girl, to Heaven. The Girl's innermost desire is to be with the Guy for eternity. What kind of Heaven will the Girl experience?
Would the god bend the rules for the girl so she can be with her lover? That would be unfair for everyone else. Would the Girl be ineligible to go to Heaven for loving an Atheist? That would be petty. Would the god create an illusion of the Guy that the Girl will love? That'd be cruel. Will the god strip the soul of its senses so that it can only experience unconditional bliss? That'd be even worse.
Here's the easiest way to get to "Heaven". Take Acid.
