This is something I think about a lot. We all know pure rhetoric is never going to deconvert someone, but a combination of "dark arts", emotional vulnerability, and personal connection seems a likely recipe.
A quick summation of how I feel about religiosity: I hate the belief, but love the believer. I went through a long and painful deconversion process, so I can empathize with them. I know that religious people struggle with doubt and are probably terrified by the prospect of losing their faith. I've had the chance to go for the throat (so to speak) several times, but never had the conviction to do so.
So I guess the question you have to ask, is, what are you offering them in return? Keeping in mind that they are probably more of a "normal" than you are, how is it going to effect their social and psychological well-being? Do you anticipate that changing that one belief will manifest itself in greater mastery of rationality, or even a glimpse of the path? Or are you just stealing a childs safety blanket and telling them to grow up?
The only other mitigating factor I can think of is "raising the sanity waterline", specifically by decreasing the overall population of virulent religious memes. But aren't there probably better and easier ways of doing so that don't involve randoms going through bleak existential withdrawl?
That's a serious question, I'm not settled on the issue at all either. Of course, there are some people who will just need a push, a friend to tell them it's ok. If they seem like they can thrive as an athiest, due to humanist values, being contrarian, courageously facing the truth, or whatever, I don't see why not.
I'm not sure if this is precisely the correct forum for this, but if there is a better place, I don't know what it would be. At any rate...
I'm a student a Catholic university, and there are (as one might surmise) quite a lot of Catholics here, along with assorted other theists (yes, even some in the biology faculty). For this reason, I find myself acquiring more and more devoutly Catholic friends, and some of them I have grown quite close to. But the God issue keeps coming up for one reason or another, which is a source of tension. And yet as I grow closer to these people, it becomes clearer and clearer that each theist has a certain personal sequence of Dark Arts-ish levers in eir head, the flipping (or un-flipping) of which would snap em out of faith.
So the question is this: in what situations (if any) is it ethical to push such buttons? We often say, here, that that which can be destroyed by the truth should be, but these are people who have built their lives around faith, people for whom the Church is their social support group. If it were possible to disillusion the whole world all at once, that'd be one thing - but in this case my options are limited to changing the minds of only the specific individuals I have spent time getting to know, and the direct result would be their alienation from the entire community in which they've been raised.
And yet it is the truth.
I'm conflicted. LessWrong, what is your opinion?