The modern, rabid liberal despises Christianity and if they could, would kill every single Christian. Why?
Christians are the antithesis of everything they stand for and liberals cannot stand any opposition. It's not just good enough for them to silence it; they must eradicate it just like the Nazis, Soviets, and Chicoms did.
Also, deep down most people know right from wrong, and Christians remind liberals that they are wrong, especially when it comes to morality. They just cannot stand this which is why anything about God (but strangely enough not Allah) is like sunlight to a vampire.