As the good Reverend points out, this is the flaw in the argument. He has good reasons for not preventing evil: because doing so would require the elimination of our ability to make decisions independently of Him.
But why does God allow children to suffer? I've struggled with this question for so long and I haven't been able to find an answer. I am agnostic only because of this issue. I really want to believe.
Adults have free will but children don't. They're at the whim of the adults around them. I can't understand how God can see innocent, young children being murdered and not do anything to stop it. They can't defend themselves, so shouldn't God do it for them?
I'm not trying to challenge anyone's beliefs. I really want to know why this happens and I'm hoping that someone can give me an answer. As I said earlier, I've been struggling with this for years.