If they had a religion DLC for a Sims game, I think it would be best to let players construct their own religions, with the options to set whether they're monotheistic, polytheistic, or atheistic (yes, there are religions without gods), and to set alignments and attributes of any deities, spirits, or other entities which exist within that religion. Even being able to set whether those gods and spirits are actually real and able to appear and influence your sims' lives or if they don't exist anywhere but in the minds of believers should be a thing. It would definitely open up some awesome storytelling opportunities.
I mean, think of the possibilities of a story about a sim having a crisis of faith, or of making the Greek/Roman gods as actual gods instead of having to settle for making them Spellcasters and having them operating in a modern setting, or creating your own insane deities, spirits, and other divine and devilish beings to watch over or screw with your sims. Heck, just think of the possibilities with demigods, half-demons, and so-on! So much fun to be had, so much story potential!! You can create your own modern myths or sequels to ancient ones! Oooh, and just think of building your own Dark and Divine realms!! But...that's all just a pipe dream...
