In a popular interview posted on YouTube, scientist Leonard Mlodinow, who co-authored The Grand Design with Stephen Hawking, declared, "Science shows that God is not necessary to explain the universe." He also adds, "I find it very hard to see how people could believe in the Bible." But then Mlodinow gave this very surprising answer to another question on the same interview:

I tend not to believe things that there is no evidence for. But it is not always true. I do believe, for instance, in aliens. I believe that there is life on other planets, and I think there is no evidence for that. We don't understand the origin of life on Earth well enough to say how probable it is that on another star life would form. But in my heart for some reason I find myself believing that.

Christian apologist William Lane Craig commented on this quote:

That is really bizarre, isn't it? That he believes in aliens even though he says he has no evidence for it, but he just finds he believes in his heart that extraterrestrial life exists. But he doesn't apparently find it in his heart to think that God exists the way many people do. If he thinks he is rational in believing in aliens, why isn't it rational to believe in God?