The thing about Atheists is that they generally make many of the same fallacies as religious folk. This is in fact, why I consider Atheism to be a religion. They have principles, people who spread their gospel out to all mankind, and a view on providence and how the universe operates on a spiritual level.

As for the morality of religion in general: Religion has no particular ethics, it's a tool like any other for one to better themselves by creating understanding or illusion of understanding of the spiritual nature of the cosmos and the purpose of its believer.

As for Christian Ethics, I can testify first-hand that an extensive reading and re-reading of the bible does not make one into an atheist. Despite everything, I still hold God to an ethical standard that I would find utterly unreachable in humans.

As for the topic of religious extremism, there's only ever been one Christian extremist. His name was Jesus Christ. I do not consider mimicking him to be at all immoral.

As for the topic of "if I found out God doesn't exist, would I rape and murder?" No. The way I see it, whether or not God exists is somewhat irrelevant: we must act like he does. Even barring that, the Atheist equivalent of my worldview would be Objectivism (my main and basically only criticism of which is its materialistic, atheistic nature). Even barring that, I don't want to get arrested.

To turn the tables: If you found out that God existed, what would your response be?