To paraphrase William of Occam: "All things being equal, the simplest solution tends to be the best one."
Now, William was a religious man; however, his principle (known as Occam's razor) is frequently used by atheists, scientists, and other clever people to argue against belief in god. Here's approximately how it goes: Existence is mysterious. God is mysterious. To explain existence by trotting out God is to simply to compound the mystery: we haven't actually simplified anything. And the added mystery is arguably even more mysterious because it asks us to lay aside reason (omnipotence? omniscience? AND omnibenevolence? In this world?). Surely a hypothetical creator requires an even greater explanation than the phenomena that it's meant to explain.
That's like saying, "Hm. Broken window. Wonder how that happened. I do see a baseball lying there in the broken glass, and y-e-s-s-s-s.... those are some 9-year-olds running away and whooping with laughter, but I have my doubts. Yes, I have my doubts. No one actually saw the ball leave the tip of their bat and crash through the glass, right? In that case, I'm gonna go for Tash. Tash was responsible for this, mark my words. Oh? You don't believe in Tash? Just because there's no evidence for his existence? Well, he's shy that way. It's part of his...."
Oh, that should do it. I think you get where I am going with this. Surely the simplest solution is the 9-year-olds, right? You all agree with me there? So why is it that for the most important of question of all, so many of us would rather choose the more mysterious and complex answer over the simpler, more reasonable, and scientifically sound alternative?