People are judgmental no matter on their beliefs because:
- they don't know to behave differently,
- they don't understand others,
- they are scared of unknown things,
- they are blind - not thinking by them-self,
- they are centric oriented : me, me and only me
those are just couple of things that I've learned on my own skin. I'm coming from multicultural country where Islam and Christianity is completely equal in social terms. Same goes for human limitations - it is the same no matter on religion...