"So as a result, committing yourself to rationality doesn't actually commit you to an outcome, as perhaps following a scripture would."

Doesn't committing yourself to rationality commit you to the outcome that so and so "will be rational"? I'm not saying that this is the same exact thing as what evangelical christians do, where they actually twist the lines to reason to their preferred conclusion. But it's like Jack said, don't dupe yourself into thinking none of the problems with labeling will apply to you. That's where you get into a tricky place, because you are ignoring a piece of information that does not jibe with your preferred view of yourself.