For the sake of this forum, I will examine from the position that all beliefs, including all religious beliefs, have stemmed entirely, 100% from people, with no exceptions.
If so, that would mean all the religious beliefs- which people have based things on- would have that origin, as would every other belief upon which things were based.
So, to posit a world where some of those beliefs were never developed, the question is, what would such a world be like?
We're not imagining a world of magic and dragons here, we're imagining something deterministic and "realistic" (not fantastical.)
I would expect it to look almost identical to our world.
As has been pointed out, technology may change over time, but man has not changed. Improving technology has made some changes in society possible, but man is still man.
We have the printing press, which helped to try to usher in universal literacy (a radical concept for history, and a recent one.) We have the internet, where someone can use that literacy to read things all over the world. We have the potential to have the best-informed Earth population EVER.
Do we have it NOW? No, we do not.
People go into an echo chamber and don't get impartial, fair and neutral information on things, just a lot of bias confirmation. (Can't blame ALL of that on Facebook, even if they made it easier.)
What happened?
Technology may have changed, but man has not changed.
Hippies tried to eliminate capitalism, and make things free for everyone. It failed miserably.
What happened?
Man has not changed. MOST of the people went along with it. But it only takes a few freeloaders to ruin things. A minority of people showed up, and sponged off of the hippies, and tried to get everything they could (including "free love.")
So, I could see the brands changing- from religious to any other brand. But I'd expect the same problems with a few cosmetic differences.
Man has not changed.
So, maybe somebody makes their identity in a philosophical group, or a political group, or even their bowling league. But there will be sectarianism, and sabers rattled.
People form societies, and take on labels, and take on "who is an outsider", which strengthens group cohesion. That's going to stay the same as long as we HAVE people.