Have you ever convinced a religious person to become atheistic?

Yes, a few dozen, exclusively through my writing.

My impression is that the arguments have almost no effect. What has an effect is being smart, likable, and altruistic, while occasionally mocking religion and sending signals that being religious is socially uncool.

I don't know of anyone who argued someone else into atheism, ever. (Of course this may happen, but not so frequently.)

But I know plenty of people who were swayed by being a third party to a good discussion, or by reading someone else's ideas as a passive observer.

This suggests to me that Task #1 is finding ways for people to engage with your ideas without involving a status competition between you and them.

At least a few, online and in person, possibly more than I'm aware of. One person mentioned that he'd become an atheist as a result of observing my online debates over the course of a few months, but he never went out of his way to tell me, I only learned from following a later discussion; there might be others I've similarly influenced who've never told me.

Unlike Luke, all the people I know I've caused to convert professed to have been swayed by my actual arguments (and a fairly common reason for conversion I've heard is "I followed online debates and the atheists always had the better arguments,") but I've never known it to happen as an "aha!" moment upon being exposed to a single knockdown argument. In my experience it's always taken prolonged exposure to atheistic arguments for a sense of familiarity to build up, after which the person can have an "aha!" moment and realize they have somewhere to go from there.

Different people tolerate different demeanor, but I've never known of anyone converting someone else without making themselves likable to their targets.

In all the cases I can think of, conversion has taken a minimum of a few months of exposure to atheist ideas.

My brother's opinion of religion changed after he had to study Catholic theology because our young cousin wanted him to be her Confirmation sponsor. The guy who was his tutor was very much the "holier-than-thou" type and he found the actual positions of the Church on various social issues repulsive.

So that's one way. ;)

I have an anecdote, but my situation is probably not representative. I started out as an evolution-accepting theist who didn't belong to an organized church. I'm pretty sure I believed instead of belief in belief, but since my beliefs didn't match those of any organized religion, I didn't have a community of other believers around me.

I was converted to atheism by watching atheist youtube videos, to which I was introduced by a series mocking creationists. When I realized that the smartest, most science-savvy commentators were atheists offering good argumen... (read more)

Hopefully this is beneath us, but it seems that Flirt to Convert is a pretty common and powerful technique that religionists use to obtain converts.

I think from my own experience a conversion is just a switch of tribal affiliations. That means, it takes two components:

1. a sense of rejection from your previous community.

2. a sense of connection to the new one.

So the reason why indirect arguments seem to work better would be because if you argue directly you don't normally argue with someone but against them which reduces if not reverts the sense of connection. If my theory is correct then in direct conversation a more socratic method would be better. But you will probably not be successful until you somehow disconnect the theist from his circle or catch him at a time when he feels somewhat disconnected.

I was told once that things I said in english class helped convert a friend of mine to atheism, but this was so long ago that I can't really remember what I said. In terms of my own experiences of giving up beliefs I've had, a key factor is readability and honesty in presentation. Things like Yvain's non-libertarian faq are fun to read and seriously strive to address the viewpoints that I formerly held as a libertarian. It didn't make fun of libertarianism, but allowed it to reveal its own silliness by talking about it.