The stories and claims which religion puts forth justify and require certain types of behavior. The typical rationalist approach finds fault with religion because of religion's irrationality and reliance on gullibility. Listening to religious people, one would think that they would generally prefer not to be close-minded, intolerant, etc., but for the revealed "truths" of beliefs. Religion and the thicket of beliefs and stories justify a way of life. The question is most definitely not "Are a religion's belief's True?" but "What are the ethics and the way of life that these beliefs and stories glorify?"
A person chooses their beliefs and superstitions not because of an arduous (or even not so arduous) search for truth, but because those beliefs and truths justify, explain, buttress, extend, and often articulate preexisting beliefs and attitudes. A person does not become a Christian because of a belief in the truth of doctrine, one becomes a Christian because of a propensity to blindness, irrational belief, and gullibility. Or less controversially phrased: one believes, because one needs to believe.
The stories, myths, and doctrines of Christianity in this view can be taken as a kind of sign language and expression of the believer's drives, passions, and fears.
This also means that reason and rationality are not tools to get at truth. The "product" of critical inquiry is not truth or anything so final. The propensity of the religious towards blind obedience. as well as to reject of rationality as means to truth, make clear that the justification, and purpose, as it were, of reason, rationality, and critical inquiry is not truth and a more accurate understanding of the world around us. Reason, rationality, and critical inquiry find their justification and raison d'etre in the enhancement and furthering of individual autonomy.
By way of clarification: my three-year old has in the last couple of days been seeing monsters in her bedroom when it's time for her to go to sleep. She is anxious about going to sleep (most likely a variation of separation anxiety). Her line of thought goes because she is afraid, there is something to be afraid of. First the feeling, then the invention of the cause of the feeling.