Real world religions, ideologies historical figures?

Personally I don't like having RL ideologies and religions included, though it depends on the way in which they are mentioned. I don't cringe when someone mentions communism by itself, but I would cringe if someone mentioned Marx and his life, or if someone started mentioning Catholicism and the Vatican or Islam and Mecca. I think RP should involve coming up with our own explanations for major ideologies and religions.

That's just me though. Since this is The Agora, I welcome discussion.