"Believe" implies that there's no proof and we just go on the authority and influence of someone with higher rank than ourselves. It's actually a very efficient mechanism that human society has developed for controlling people. Instead of the chief needing to commit hunters to being keeps of "Law and Order", having an ally in a shaman, priest, voodoo man or other master of the spirits, allowed exertion of discipline over vast populations with the minimum of effort and the least spilling of blood.
With education of the masses of humans, one would think that a call to belief would be scoffed at more often. However, we seem to have a great need for saints, saviors, people to follow and adore. I'd venture that there have never been in the entire history of the planet, so many "believers". Add up the devout Christians, Muslims, Jews, Hindus, Voodoo worshippers and adherents other sects alive to day. The number today is likely to be over 2 billion souls out of about 8 billion total.
The non-believers are strongest in the big cities, especially near the coasts. However, religious belief, leaping into the void with no logic, just faith, is still a dominant human condition.
There's a purpose in everything, at least; that's a hope!
Asher