Okay, first off I am not anti-Christian. I am anti-Christianity. There is a difference. I hate the ideas, not the people. That said, I am also anti-Islam, anti-Jewish, anti-Mormon, anti-Buddhist, and basically anti anything that relies on faith and not fact.
However, in the short term, I really don't see most of those as a problem. While I do despise a lot of what Christianity is about, it isn't my main focus. Islam is. I think we can all agree that Islam is the main religious problem we face today, because it is still stuck in the Dark Ages. Christianity has more or less been tamed by modernism. I mean, you don't see Christians taking slaves anymore, or burning people at the stake, or claiming whole swaths of land in the name of their Lord. But Islam still does, and its ideas about freedom and equality are all but nonexistent.
As for the proof or not of the existence of God, I deny his (or her) existence because there is no proof in his (or her) favor, so why should there be a 50-50 chance that I am right or wrong? I mean, you don't see people go around saying "just because there is no proof, doesn't mean the teapot or the flying spaghetti monster doesn't exist. You could be wrong. They might just exist".
There is no proof, so therefore there is no logical reason to even contemplate whether it/they/he/she exists at all. I don't waste my time worrying about it. Of course, I cam agnostic to the idea. Obviously you cannot prove 100% that there is no god. But I hate the term agnostic, and all of the wishy-washy, non-commitment that goes with it.
My main problem with religion isn't with God, but with the fact that so many people believe and sometimes dedicate their lives to things that have absolutely no basis in fact, and can therefore not be verified. There is no sane reason to believe lies.
Also, the difference between science and faith (if it must be reiterated again) is that religion is based on false-truths and lies, while science is based on the best knowledge known to man, and is constantly changing and evolving; something that faith and religion consistently show it is unable to do.
And I find religion far more arrogant than science, because it claims things no human can possibly know. It bans and condemns freethought and ingenuity, and rewards obedience and servitude.