The whole "be nice to people" is a small part of Christianity. Furthermore, it is not in any way necessary to have Christianity (or any religion at all) to want to "be nice to people". While Christianity might implore you to be nice, it also carries with it severe baggage; homophobia, misogyny, intolerance, and fear. Seriously; if you told your child that you were going to throw her in the furnace for being bad, it would be child abuse; tell your child that God will throw her in a furnace for all eternity and all of a sudden it's OK. Christianity is a festering sore on our moral development, the sooner we can be rid of it, the better. I will close by passing on Hitch's legacy in the form of a question that he was fond of asking believers: Name one good, moral action that could not have been conceived of by a person of no faith. Tough question, right? Ok, here's an easier one: Name me one wicked action that was committed in the name of religion. Chew on that one for a little bit, and the cognitive dissonance might wake you up from your intellectual coma.
Throwing your child in a furnace is child abuse; threatening that you will is just bad parenting. But that is a pretty fair comparison.
So, one wicked action in the name of religion makes religion bad, but clearly you don't feel that one wicked action in the name of something other than religion is bad, so only religion is bad? I suppose if you believe that right and wrong exist only with respect to religion then a non-religious person can't possibly do anything wrong because there is no wrong.
Now, has religion - Christianity or otherwise - been used to commit horrible atrocities? Absolutely. Does that mean religion is bad? Well, if one is in the practice of ascribing evil to inanimate objects, then I guess it is. I, on the other hand, think people are to blame. And "most people" are nothing. Rather, we are just inundated with bullshit from a very loud few. When a person blows up an abortion clinic for Jesus or blows up a crowded disco for Allah, their ignorance is projected onto the lives of many innocent people, and that is truly a tragedy. But once again, let's not lose focus on the fact that people do this shit, not their religion. If any of you religion haters spent any amount of time with typical religious people, you would find they abhor blowing shit up as much as you do. Yes, even the nice ones often let their belief cloud their otherwise intelligent minds into ignoring some really good science. And yes, sometimes large groups of people get stirred into a frenzy (crusades, witch trials, jihad), but other than jihad we are pretty much passed those days.
For the record, I am not religious or christian or anything. Since there is no way to prove the existence of god, I think believers and non-believers alike are both wrong. It's not that one has the wrong answer; it's that neither is answering an answerable question.