Did you know there was a cult that exists that worships Satan? How many people in your society would you say have heard about Satan? Do they think a Satanic cult is good or bad? I'd you met some random woman, and she was wearing an upside down cross on her chest and a pentagram on her forehead and shoulders, and those pentagrams were as big as the sun, and you found out she was a priestess of some religion, do you think it would be NOT obvious who she was a priestess of?
Shar is like Satan in FR. She is well-known and feared and detested. And yes, maybe some would not know her symbols, but many would especially Gale and druids in the Grove.
Well, this is too easy. There are populations in Africa today that are cut off from modern society, some by choice some because they're next to impossible to get to, and they wouldn't have a clue. Stepping back 200ish years, the Native Americans had no idea. Christianity ran roughshod over most of Europe and parts of Asia, but always managed to find "heathens" to convert. Was God less immortal back then? It's not hard at all to imagine that some people wouldn't have an idea about who this God or that Goddess was if they hadn't been exposed to them at some point.
