Well, um... getting back to our main topic...
Religion separates people. This is true. But how many other things separate people? Money. Race. Values. Place of birth. These are all differences that separate people from each other. If somebody is willing to kill someone else over something as petty as a difference in religion, then they will be willing to kill someone over something else, if religion is taken away. Few, if any, actually kill people because God told them so. They kill people because they are different. They kill people because they have an honest belief that the other person is something to be hated. Religion can cause this. But so can a multitude of other things.
If you waved a magic wand, and made religion disappear from the world, you would not remove the root cause of faith-motivated violence. That root cause is the warped values of those who perpetrate such violence. For some reason, there are people on this earth that you and I share who value the lives of others less than their own personal beliefs. Religion is used as a motivator by these people, and it gives them a "cause" for which to kill. If there was no religion, you would still have people who are willing to kill. And then you would have hate crimes, and gang wars. More of them than there are now.
And do you know what? When you get down to it, religion is just philosophy. If you remove religion from the world, do you also remove all philosophy? Or do you just remove all philosophy that involves a deity? Better to remove all philosophy, isn't it? Because people will be willing to kill over that, once you magically ban deities. I mean, what's to stop me from creating a movement of my own, with a vast following of people who hate other people, where I preach that others are unworthy of life, because of whatever reason? The Nazis weren't following a religion. They held a philosophy.
So, what then? No philosophy? We can't think? We can't form a system of beliefs about the world and how we should live our lives? You want us to be zombies? Well? If you want free will, you have to take everything that comes along with it. Remember what the Supreme Being had to say about the existence of evil, in Time Bandits: "Ah... I think it's something to do with free will."