The Pathfinder third party setting
Kingdoms of Legend proposes an interesting prospect: an alternate Earth where Elves, Dwarves and Gnomes were the "Old Races" of the world, displaced when Humanity arose with their first Empires, and where Monotheism never happened, with the world's deities being the Greek Pantheon, known by other names in other lands.
It's an interesting concept, to be sure, but it does leave me thinking that removing Christianity and Islam tends to deprive the Medieval Period of it's "flavor", as it were.
So it got me to wonder about an
alternate alternate setting, one in which Christianity (or, to be different, Mithraism, maybe?) co-exists with the Old Pantheons in a more syncrestic relationship. Let's assume, for a second, that Christianity never became powerful enough as a political force that it Christians could just eliminate Pagan faiths. How would you make that work?
Could you make that work?