If you say something bad about Mohammad, there's nothing wrong with that, as long as it's true (and there are a lot of true bad things about Mohammad). But if you paint all people of a religion with the same broad brush, and put collective guilt on people for the actions of individuals, that's bigotry.
That won't work.
Truth by itself is exclusive. Two contradictory statements cannot both be correct, or else truth itself is a casualty. This is the law of Non-Contradiction.
The problem is that one side of the debate may call truth "bigotry."
Either there is a spirited debate here, or there is not. Moreover, I have no problem posting my beliefs of biblical Christianity and being challenged on them. Anyone is free to do that here as far as I am concerned.