Some believe the religions came from the heavens, some believe not. Curiously though, 3 of the biggest religions of on Earth seem to originate from a relatively small area in the Middle Earth: Judaism and Christianity were born in todays Israel/Palestine (practically on the same spot) while Islam was born in nearby (at least in relative to the size of the Earth) Mecca in todays Saudi Arabia. Then we have the other 2 big religions, Hinduism in Indian subcontinent and the Buddhism is East Asia.
All these religions which are often used as pretexts for wars have a lot of similarities though humans are good at focusing on the differences…
One thing is certain: They all started small with few followers who often paid hefty prices for being different from the mainstream (though once those religions got massive, the following generations made other “different” people more than pay for what their pioneers had endured in the beginning..).
Anyways, once they started small, how did they geographically spread all over the world? This animation shows you just that, albeit without taking into account the further divisions in these religions like Catholicism, Protestantism, Sunni, Shia etc. (honestly everything is already complicated with that additional complexity).