Are there any deities whom favor balance between good and evil over all things? Less emphasis on war/valor/tyranny than Heironeous and Hextor, less about magic than Boccob. I'm looking for a deity or even established (published open content or homebrew) religious organization that would be well represented by something such as the Yin Yang, close to Taoism.

I'm a DM looking to incorporate these elements into a campaign I'm making and am hoping there's a precedent I can borrow from, shamelessly and heavily. The game's primary theme is going to be perspective on good versus evil, and a religious cult or two following this deity will be warring with each other and the character(s) over ideological differences in interpretation.