I recently came to a different conclusion. It's not religious faith. It's just faith. And it's not a mental illness. It's human nature - for a significant segment of the human population.

Those people who are religious fanatics, political fanatics (e.g. Trumpists, Chavez sympathizers), pseudoscience fanatics (e.g. flat earthers, anti-vaxx, homeopathy), celebrity fanatics (Andrew Tate followers), etc, they have to share the same common traits. They're impressionable people, they need to be patt of a group, and they can't fathom the idea of switching groups.

It's just that religion-based control came first.

Or maybe those who were very religious in the past got to survive and thus the genetic traits responsible for fanaticism spread like fire?

Regardless, it's appalling.

People in the past weren't us in different clothes and religion was basically fulfilling political and cultural functions as well. Like today was have mass media and entertainment, at one point religion was basically entertainment as well. People loved having some preacher come to town and do his show, it was what people talked about. Now we have TV shows and movies etc, and a lot of our media has shocking moral implications just as we'd judge religion in the past for. Not all that different. That leads in to civil/civic religion which is practiced by many today and provides a framework for things like a national identity. When you stand for an anthem you're performing a civil religious ritual, visiting historical/cultural sites is a sort of pilgrimage.

The form that religion evolved through in history was also defined by the conditions of the society and a lot of times compromises with neighboring powers. Viewing religion as a dumb thing for stupid people is intuitively tempting, but it's ahistorical in that it says more about our views today (including religous/civil religious views) than it does about what people were like in the past.

I mean you might be kinda right?

So there are people who think with or without internal monologue, common knowledge

Some people think that the internal monologue may have first developed as an internal dialogue, between the actor, the person and their body, and the "speaker" who they would have not been able to recognize as their own voice, and instead interpreted as a separate being relaying them direction, commands, and interpretation.

The dissociation between the individual and their internal monologue, and the resulting association of that monologue with a directing and counseling presence, could have been taken as the voice of a higher power guiding them, and by extension, others they got to follow them as the "speaker" of this divinity in their head.

If this sounds a bit crazy to you consider how many evangelicals rant and rave about their personal speaking term relationship with God.

So basically, deific religion might derive from people who have an internal monologue but who don't identify with the speaker of that internal monologue.

Not really a mental disorder so much as a mode of thought that is prone to lead people into believing firmly that they are personally in contact with a separate being who personally directs their behavior and actions and values.