Yeah, I've been trying to put that off because it (edit : religious thinking ) isn't something I really think about in my own life.

Religion arose as a means to understand the world. It was a defence mechanism for when people had no idea what happened and what were the reasons for it. Sure, tigers ate those humans who came too close - that one was blatantly obvious - but given our innate tendency towards wishful thinking, those of early protoreligions considered that, maybe, if one does something to please the tiger (or, the idea of said tiger, for the tiger itself is intangible while away), it'll stay away, not attack.

Then it snowballed from there. Some people got in power by asserting that they have contact with the spirits/the gods. Some good people tend to serve those in charge by believing into whatever the religion posits as the truth. Different believers felt differently about the truth and broke off with their own interpretations of the teaching (Christian branches). Others got inspired and made teachings of their own (Christianity from Judaism, later Islam from Christianity). As with any sort of thinking, religious outlooks take all shapes and sizes:

- "There is god" or "There are gods" (theism: mono- and poly-)

- "Maybe there is god; we can't be sure" (agnosticism)

- "There is no god" (atheism)

- "There is god, but he/she no longer takes part in the world" (deism)

- "I can be god" (autotheism)

- "Spirits guide the world" (animism)

- "God isn't a reliable moral source" ("God is dead")

- "God is and is good" / "...is not good" / "...is evil" (eutheism / dystheism / misotheism)

...and a lot more. I want to keep going - there are so many interesting belief concepts around the world, barring even those you can constuct yourself - but I'm sure you'll able to navigate the front without me.

It's telling, too, that once science gained traction in Ancient Greece, mythology lost its: people had a new, objectively better means of understanding the world - one that actually grants information.