The Mantle Creation Myth

"The Avatars, most supreme of beings above all, created the world we live on. Idiomar, of rage and love, forged the deep and violent places of the world. Suthan, of intelligence and logic, crafted the high and lofty places. And Lethaego, of peace and calm, tempered the three and created all betwixt. From their power the moon, stars, and sun came into being. The Sun to give their creations the ability to change their world. The Moon and Stars to return that energy for even further generations and seats for those that would come after. From the Sun and Avatars came the Gods. The living embodiment's refining the aspects of the Avatars. Thus the world was created, thus our world was formed."

Summary

It is told by the followers of the Mantle that the three Avatars: Suthan, Idiomar, and Lethaego created the universe. From their immortal, all-knowing, and all-seeing power they created and maintain the cosmos and all who inhabit it. They left behind the Sun as a source of energy for all beings to draw on to help shape their world. The moon is where all energy goes when dispersed, to be brought back to the sun. Essentially the sun gives energy, the moon receives energy, and so the cycle goes forever. The Stars serve as the seats of the other gods.  The minor Gods, or other Gods, are byproducts of creation. They amplify and represent the Avatars, and are embodiment of their true power. As Hakir has shown, even mere mortals can ascend to godhood. Though there is much debate about how he did so. Some Elves say that Elves losing power in the world necessitated that the Avatars raise another god to adjust for this loss of order. Mortals say that his ascension is because the Elves had messed up the natural balance so much him raising to godhood was needed.

Historical Basis

Radiant and Holy energy certainly exists and clerics and paladins can call on their god for magical and miracle based means. And priests and paladins speak of hearing their gods. The gods play a role in the comings and goings of the world (though the exact details are debated), including helping save it during The Return.

Variations & Mutation

Certain cultures say that the Avatars did not come until after creation, but their "raw form" as primordials was responsible for creation.