Dude. If I played D&D tabletop with a new player, I, the DM, would explain who Shar is to my player. I would not say, "Look Shar up on the internet.".
As soon as Shar or anything Sharran related popped into the story, I'd make the player roll a Religion roll.
If they got a 5 or higher, I'd say, "You think you heard about this before, but the details are sketchy. She's a cleric, and her spell focus is an onyx stone. You think it might be to an evil goddess."
If they got a 10 or higher, I'd say, "You're not sure, but that could be the symbol of the evil goddess Shar, goddess of darkness and loss. Her cult is known for violent, wicked acts."
A 15 would be, "That is a symbol of Shar, most definitely. She is the goddess of darkness and loss. Her cult is violent and evil and it is very secretive. She is one of the primordial deities of Faerun, and she has a twin sister named Selune, goddess of the moon and light. They have been at war for countless centuries."
A 20 or more and I would tell the player all the above and say, "You know a LOT about Shar. If you run into anything additional that is Shar related, I'll just tell you about it and point it out. In fact, if you want to know more, look it up online. Your character knows all that you can find about Shar online."
I would most certainly NOT make my player look it up online. My players would lynch me. Why should it be any different for a video game? They can literally tell you in a few lines who Shar is and make it a part of the game that you, if you don't want to hear it, can literally hit the space bar and skip and players who know nothing about Shar would not be so totally lost.
This is apart of D&D people. It's a HUGE part of it. Players are not supposed to be expected to just magically know all the lore themselves. That's the DM's job.
Yes, because no TT session ever had players with a Player Handbook, or any of the other myriad of books aimed specifically at the players, right? You must have to spend a few sessions in a row, just explaining things, since you don't require your players to have resources created specifically to prevent that. You see, the problem with trying to translate your TT experience into a video game is that someone around the table is going to have these reference books. That is specifically what they are for. I wonder, how many interruptions of gameplay does it take before your players are suggesting the new player get X, Y and/or Z books? I've played at tables where you weren't allowed to sit down if you didn't have at least a Player's Handbook.
I should note here that the comics I'm referencing are interactive comics that come with the game, and allow you to make choices from the previous game(s), I'm not sure how the ME 3 comic functions, if it gives choices from just 2, or from 1 and 2. It is included specifically to give new players some of the critical choices in 1, for the ME 2 comic.
Dude. It doesn't take much to say, "Shar is an evil goddess of darkness and loss.". Much quicker for me to inform my players of this than to have them look everything up. The DMs job is storyteller. As the story progresses, he/she informs players of things like who Shar is AS they encounter stuff. What is the point of a Religion skill if players never use it to learn stuff about deities that their characters know?
Actually, it's to provide a template for the players to tell a story, within the confines of what's provided. A story teller tells the story. In DnD, the players create the story. This is done through choices they make, dice rolls they make, or fail, and how they choose to go about combat. As a DM, you should have an outline, not a play by play, of what's expected to happen. There are around 50 years of lore to this setting, how much are you going to explain, for how long, before other players in your session get frustrated because resources are available. To your "Shar is...", there are books that cover that in game already. At some point, it's up to a player to find/read them. How many dialog wheel style choices do you provide for your players, instead of them organically asking questions? How are you going to code every possible outcome into a cRPG? The OP's issue is that there's a response that is overtly hostile, and they don't understand why. The problem is, it's not the only response available, but for some reason, it's mere existence is bad because they don't understand why it's an option. It's an option because some of us know what it means, and shouldn't be locked out of that response because a new player doesn't understand it. This is the equivalent of you sitting behind your screen saying "You can't say that because Josephine is new, and won't understand why you feel that way".