I liked this post.

Note that "Wannabe Rational" is not terribly different from "aspiring rationalist" -- the very term that most LWers use for themselves!

All of us, presumably, have some beliefs that are not accurate. That, of course, makes us irrational. But we'd like to be more rational. That desire, that aspiration, is the entrance requirement here.

It's true that there is a limit on how rational you can be and still be a theist. But that's not the same as the limit on how rational you can become in the future, given that you are now a theist (or have whatever incorrect belief X).