Speaking of Stephen Colbert, Brian Leiter links to this clip of Colbert 'refuting' Bill O'Reilly's 'proof' of God's existence. I'm not a huge fan of O'Reilly, but I think there is more to his point than Colbert (and most of his audience) realizes.
O'Reilly says that he believes in God because the tides, the moon, the Earth, etc. move regularly. Colbert (who believes in God, in case that seems relevant) responds that the tides are regular because of the moon, and its movements are regular because of the laws of physics (e.g. gravity), and so there is no mystery to solve by positing God.
Positing God will not solve any mystery because God is mysterious. And the existence of a mystery does not prove the existence of a mysterious Being. But I imagine O'Reilly has been influenced (directly or otherwise) by GK Chesterton here. Chesterton does not offer an argument for the existence of God but does explain in his spiritual autobiography Orthodoxy that one reason he believes in God is because he was struck by the regularity of the universe. It won't do to respond that the laws of physics explain this regularity, because it's equally possible to be struck by the existence (or possibility) of these laws. In a nutshell: why should the universe behave regularly (i.e. in such a way that it is possible for us to identify laws of physics)? And why should they be such desirable laws, allowing (e.g.) for life on Earth?
Internalizing these laws as mental operations (as in some forms of idealism) just relocates the mystery in the mind instead of 'out there.' Perhaps there are other forms of explanation that might take away the sense of mystery, but it is something that has struck many people, including non-believers. If you're like Hume you can shrug it off as a curiosity and go to play backgammon with your friends. But this might seem a little shallow. If you're like Sartre you can be sickened by the experience of having to rely on a universe that there is no reason to trust. But that seems a little melodramatic, not to mention unpleasant. If you're like Chesterton you can express your amazement and gratitude by living a religious life. But that might seem superstitious or sentimental to some. (Wittgenstein expresses some concerns along these lines.)
So it isn't obvious what to do with this mystery, and O'Reilly's (perhaps rather too confident or even self-satisfied) response is not necessarily the best one. But wheeling on a physicist to talk about gravity doesn't really address it at all. Except to encourage laughter in place of amazement. Which beats nausea at least.