Nobody is saying that. But if you for example believe that slavery is right because Bible says so, well, we have a problem here, don't you think?
Actually I'm starting to wonder about the whole idea that you can't fire someone based on their religious beliefs (at least I understand this is the law in the US).
What if I discover one of my employees donated to a political group that is trying to bring back slavery. I definitely wouldn't want someone like that working for me. But I can't let them go because their religious book says slavery is fine and their religious views are protected?
Crazy world.