Transition over to a society filled mostly with uneducated peasants, all split apart by assorted boundaries. In a land filled with numerous races and monsters and bandits and wizards and this symbol and that symbol. No, the average person doesn't know a tenth of what the typical Forgotten Realms fan does, especially considering the fan has probably spent years reading setting books.
I agree with this entirely, most people would only know of the gods pertinent to their lives. Those with higher education and perhaps in large cities where there are temples of all types, and of course adventurers would know a bit more. However this doesn't help the situation of the player being confused, so I think more knowledge should be given somehow.
Ineducation is not ignorance. Peasants are not dumb. They'd full well know who figures and concepts central to their religion and culture are. Travel back and ask a French 12th century peasant who Satan is and they'll tell you. Go to a 50 BC Jewish peasant and ask them about the Shaitan the Tempter and they'll answer. Head over east and ask a Zoroastran who the Adversary is, or up to the North and ask about Fimbulwinter and you'll get an answer.
Now go ask a Faerun peasant about why the moon changes every month and they'll answer "it's because Selune is locked in eternal battle with her sister Shar, who seeks to bring darkness to the world, and the moon waxes and wanes as they fight". Even the most uneducated mud-farmer would know something so foundational to the mythos of their culture and world.
Now, I'm all for the aspect of Shar that is the twisted maternal figure, the one who promises love and then envelopes you in darkness, who draws in the broken and lost of the world. But that aspect is a chimera, a facade. And it's not what the average person of the realms would know of her, aside from scholars only the handful of people which she approaches under this illusion will know of it. And don't get me wrong, I hope that's where they're going with Shadowheart's story. But it's not the knowledge that needs to be given to the player before Shadowheart's reveal in order for them to be able to make an informed choice about their in-character reaction to said reveal (unless, I suppose, they are playing a Shar worshipper). And that is the heart of the topic of this thread. People don't feel they know why they should react to Shar being Shadowheart's patron.
