From the perspective of an athiest, everything that we feel and experience is synthesized in the brain, and we are totally dependent on the brain for personal existence. So according to this, of course heaven and hell would be impossible to experience, because suffering and joy are both just emotions being created by chemical receptors which become inactive after death.
We say, however, that even when the brain is inactive, the spirit is still capable of sensation. How? Does a spirit feel all the same things a body does? Does it feel them in the same way?
In our current earthly lives, is it possible to differentiate between what our spirits feel and what our bodies feel? Can we theorize about what it’s like to “feel” after death, or will it be an experience totally beyond comprehension?