I'm an atheist, who is pretty firm in my belief. My personal belief is that, assuming death goes correctly without any severe damage to the brain, brainstem or the arteries, we will experience a last, extremely vivid dream, which for many will be either their idea of heaven or a past comforting memory. This is my speculation based off the fact that studies have shown spikes in the hippocampus and other areas of the brain responsible for dreaming combined with the many cases of resuscitation which causes the individual to see their own belief of afterlife.
That said, even I am not 100% dedicated to this idea, and the possibility of an afterlife in general terrifies me. I just want to return to the absent nothingness that was before I was born.
I am more scared of living the way I do right now, the concept of hell doesn't scares me when my life here is hell.
I've talked to a Muslim SaSu member who despite fully believing they are going to hell, they were adamant they couldn't continue in life. They simply wanted to move on, regardless of what awaited them.