In my world, the halflings didn’t believe in gods, they believed in themselves and their mastery over life itself, but early in their history they saw power in the sun, the moon, the earth and the sea, the winds that let them sail across oceans. Just like primitive humans on earth, a few worshipped them and while the “modern blue age halfling” might scoff at such things, there were still practitioners of the ancient ways, especially when the magic they wielded wasn’t just trickery and alchemy but actual elemental power.
The races of the rebirth also struggled to understand the world around them. Psionics changed things but there were still those who saw power in the natural world around them, believing in the tree spirits and spirits of the rivers and such. Eventually these coalesced into religions, not of the elements but of people and personified ideas. A god of innovation who used fire with some earth and even water. The old ways again never died, but they were quickly surpassed by organized religions pushing their truths. These gods never appeared to their followers except in dreams and visions, but it wasn’t unusual for a high cleric to be proclaimed an avatar of a god or for a newly discovered group to have a similar god.
By the time of the Cleansing Wars, some of the church’s had taken sides, throwing their support behind one Champion or another, or even those they hunted. As the war progressed, many began to confuse worship of a god or avatar with that of the Champion, elevating them to godhood and sometimes replacing the original god and church. As the world around them burned, the Elementals took notice at their rapidly diminishing powers in their own planes and began to actively seek out followers on Athas to promote them. Few elementals tolerated even their sometimes allied elements and demanded their followers worship only them. Druids who had long worshipped nature gods that blended multiple elements began to turn themselves into living avatars of the land, bound to it, but with powers across multiple elemental domains.
With the age of Sorcerer Monarchs and the outlawing of reading, most religions were also outlawed. A few managed to survive to present day, but for most, they were forgotten. The only viable paths to supernatural power were the inborn psionics powers, Sorcerer Monarchs via their templarates, wizardry via preserving or defiling the land, elemental power by pledging support to an elemental lord, or being chosen by the few druids willing to teach their ways.
Every now and then, someone stumbles on the ruins of the old religions, or even attempts to create a new one, but for those who choose to investigate rather then simply believe, they find all power comes from the same sources.
