Why are some Christians so judgmental?

First of all I want to say that I respect all religions, so this is by no means a rant or bashing. I have a lot of Christian friends and they all like me and respect me equally. But some Christians ridicule and condemn me just because I'm Atheist. I believe its because Christians attribute non-believers as immoral or nihilistic, but that is not true at all. I would never hurt anyone or dare promote Anti-Christian ideas so why condemn me. Some are so trite as to say I will spend eternity in hellfire just because I don't believe in God, it makes no sense. I find it interesting how some Christians cannot respect my conviction the way everyone else respects theirs. I believe we are all equal and just because my views are different doesn't make me a demon. Why do some religious people try to play God, and damn everyone who is not like them?