While in Auburn for Mises University, I got into an argument over the existence of God. The young man arguing with me thought he had a priori proof that God couldn't exist. (We were both at the bar, so it's possible that he didn't present his case well and/or that I am botching my summary of it.)
Basically he argued that theism made no sense, because if God created the universe, then that's something out of nothing. (I will pause just to let that sink in.)
Naturally my first response was to say that God is not nothing. He asked, "Then what does God consist of?" I responded, "Love, wisdom, omnipotence..." It soon became clear that he was a materialist (or some variant of), and so thought that nothing could exist before the existence of the physical universe.
I tried showing the problems with this by asking, "Of what does Austrian economics consist? Of what does geometry consist?" (Note that you can say propositions, but by the same token I had given him constituents of God. He rejected them as silly because they were intangible, just as propositions are.)
Anyway, my point here is not to ridicule this guy; when I was an atheist I would've agreed with his stance wholeheartedly no doubt. But it just cracks me up that someone who believes in the Big Bang can say with a straight face that theism is logically nonsensical because it implies something from nothing!
(A similar example: G.K. Chesterton has a great quote--which I will butcher--to the effect that, "The fact that every civilization has a memory and stories of the great flood is somehow construed by skeptics as evidence that it is just a myth.")