It is the natural state of humanity to want answers, Especially answers to where we came from. While many modern religions are very cult like, And can do a lot of harm, The idea of a god itself is entirely harmless. It is not a mental disorder, Just our brains searching for an answer.
Many people just think... There’s no god because there is SCIENCE...And then make their mental decision that all people who believe in god are mentally ill. Have you really thought about it deeply? “God” is just a human ord trying to descibe the ‘thing’ outside of time and space, the ‘thing’ that created time and space. It’s really more complex than most people think
Nearly every single culture and society that exists or has ever existed, has generally believed in a God or a deity of some kind. It appears that this is a collective human experience, a belief that there's something beyond you that you can't fathom. Just religion, or belief of a Deity in and of itself, is not a mental disorder.