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.
Best Answer
Considering only core and "core plus" (books that mention gods as part of the default setting)…
Rao may fit your needs admirably: the Flan god of reason, serenity, and peace, his followers avoid violence—except when absolutely necessary to defend the rationally-chosen course of action. As we well know from humanity's history, many conflicts arise from the absolute conviction that your own reasoning is correct and that the break-away heretics have made a theological error in their doctrine. Raoans are ripe for sectarian disputes. As a bonus, the theme of Rao is pretty much Taoism with the serial numbers filed off, right down to the name.
You might also consider Cyndor, god of time, infinity, and predestination. The church's dogma is that all paths are predestined, which is a bit like the inevitability of the Way. Now add a power struggle on opposite sides of a prophecy, and you've got sectarian strife.
Both Rao and Cyndor appear in Complete Divine, though their Wikipedia articles alone might be sufficient if you're going to tweak their church and dogma anyway to emphasise your themes and put a fine point on your starting situation.