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.
