Typically arguments on that kind of topic contain huge number of potentially sloppy inference steps with each step having rather low probability of being valid, leading up to a very very low probability of correctness of the argument (we're speaking in the range of 10^-20 easily). It's incredibly easy to make evidence so weak it is not worth the paper it is written on. Furthermore even dramatically raising probability of validity of each step doesn't make the result worthwhile, but leads to massive overestimation of the probability of correctness of the argument because people fail at exponents. Actually I think the biggest failure of the LWism is the ideology of expecting updates on arguments with probabilities in the range well below 10^-10 , people just fail imagining just how low the probability of a conjunction can get and/or don't multiply because of residual belief of some common mode correctness as if it was oracle speaking.
A friend recently asked how strongly I believe that my deconversion from Christianity was not a mistake. Here's my response, and for those of you who are not Christians, I'm just wondering what numbers you would give:
"There is a part of me that wants to say the chance is far less than 1 percent. But when I consider what 1% must mean about my ability to follow complex arguments and base my judgement on the right premises, it seems absurd to say that.
Trying to honestly estimate the chance that I'm wrong about the Bible being generally reliable is a fascinating exercise... I know the number is low, but I'm not sure how low.
Today I would give myself a 1 in 20 chance of being wrong. If I were to consider the arguments of 20 other groups similar to Christian theologians, I would probably misunderstand them at least 1 time in 20. After talking with 20 groups that have a very different worldview, I might think they are all are mistaken, but once in a while, maybe 5% of the time, it would actually be me.
Wow, 5%!?! If I convert that into "There is a 5% probability that the God of the Bible exists and will send me to hell", I feel scared. But I know how to cheer myself up: I just say, "No way, the chance I'll end up in hell MUST be less than 5%. After all, the God of the Bible is CLEARLY just a big, mean alpha-monkey and... [rehearse all the atheistic arguments here]".
This back-and-forth from certainty to uncertainty makes me feel like I'm doing something seriously wrong.
So what about you? What chance do you place on some variant of Christianity turning up to be true, and what chance do you think a god of some sort exists?"
Numbers please.