At some point, I ran across an argument along the lines of: “We hunger, and food exists. We thirst, and water exists. We feel horny, and sex is real. We yearn for God, and so I conclude that God exists.”
Now, I can easily pick this apart a bunch of different ways, the easiest one being that just because you want some to exist doesn’t mean that it really exists. But what I’m really hoping for is a couple of counterexamples: something like “Yes, well, we all want a unicorn, too, but unicorns don’t exist.”
This particular one doesn’t work because wanting a unicorn isn’t a universal desire the way food or sex are (even counting asexual people, we can still say that the vast majority of people want sex). But maybe some of you can think of something.
No, I think the unicorn idea might be good, combined with a gentle reminder that not everyone yearns for a god.
This could work for wings, unicorns, the possession of magic powers, the end of earthquakes, the desire to see an old pet, or even Marxism:
this argument has the advantage of freaking them out so they don’t come back.
Oh yeah. They will be doing little evangelical exorcisms on themselves for weeks trying to get your Marxist demons off of themselves.