Some of that might be because of evaporative cooling. Reading the sequences is more likely to cause a theist to ignore Less Wrong then it is to change their beliefs, regardless of how rational or not a theist is. If they get past that point they soon find Less Wrong is quite welcoming towards discussions of how dumb or irrational religion is but fairly hostile to those that try and say that religion is not irrational; as in this welcome thread even points that out.

What I am wondering about is why it seems that atheists have complete caricatures of their previous theist beliefs. What atomliner mentions as his previous beliefs has absolutely no relation to what is found in Preach My Gospel, the missionary manual that he presumably had been studying for those two years, or to anything else that is found in scripture or in the teachings of the church. So are the beliefs that he gives as what he previously believed actually what he believed and if so what did he think of the complete lack of those beliefs being found in scripture and the publications of the church that he belonged to and where did he pick up these non standard beliefs? Or is something else entirely going on when he says that those were his beliefs?

This doesn't limit itself to atomliner; in my experience generally when atheists talk about their previous religion they seem to have always held (or claim they did) some extremely non-standard version of that religion. So is this a failure of the religion to communicate what the actual beliefs are, a failure of the ex-theist to discover what the beliefs of the religion really are and think critically about, in Mormon terms, "faith promoting rumors" (also known as lies and false doctrine, in Mormon terms), or are these non-standard beliefs cobbled together from "faith promoting rumors" after the atheist is already an atheist to justify atheism?

I know that atheists can deal with a lot of prejudice from believers about why they are atheists so I would think that atheists would try and justify their beliefs based on the best beliefs and arguments of a religion and not extreme outliers for both, as otherwise it plays to the prejudice. Or at least come up with something that actually are real beliefs. For any ex-Mormon there are entire websites of ready made points of doubt which are really easy to find, there should be no need to come up with such strange outlier beliefs to justify oneself, and if justifying isn't what he is doing then I am really very interested in knowing how and why he held those beliefs.