The only reason people believe in an afterlife is because they fear death. Plain and simple.
No. Its because they cannot imagine life could be pointless, absurd, there has to be something better, or at least simply something else after it. They can fathom the possibility we could just be animals randomly killing each others aimlessly until we get wiped by an asteroid just like the dinosaurs. In the meanwhile we re all struggling to survive just like vegetals and other animal species. You could die at any moment struck by a car, a robber, a solar flash just like an eagle could catch a mouse in the grass. When it happens, there s no meaning, no justice or anything it just happens.
Even in religion we categorize people and even in religion there are dominating individuals and dominated individuals. But that's because it s the same everywhere in nature; it's always the same principles, alphas, and betas. Betas want to become alphas and alphas do their best to keep their place at the top. We are "intelligent" and can protect ourselves form many more dangers than other "dumber" animal species, but in the end the elites would still kill everyone else if needed, just like alpha lions would kill another male's offspring after defeating him if needed.