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.