There's a long comment by Eric MacDonald in this thread over at Butterflies and Wheels, where he discusses the supposedly private nature of religious belief. Read Ophelia Benson's opening post, which is useful in itself and provides the context. But then scroll down to this comment, which I'm going to re-post here with a minimum of elision:
Religion is not a very private matter. It is a very public matter, and it is increasingly more and more public. How people make sense of the world, religiously, almost always seeks to impose itself on others.
Religion does not respect boundaries. For a long time it was thought that religion had retreated to the private sphere, but it had not. Religious priorities were still reflected in law and social custom, but as soon as these came to be questioned, and in many cases overturned, religions began, once again, to strive to re-establish the religious "foundations" of the culture. The introduction of an unreconstructed Islam into jurisdictions traditionally dominated by Christianity has led to renewed attempts to reassert Christian dominance.
The same thing is happening with respect to science. It is astonishing and disturbing to see someone with the apparent stature (in the scientific community) of Francis Collins making childish arguments for the consistency of science and (what turns out to be a gasp-makingly conservative form of) Christianity. This should be seen as a very deep cultural crisis. By all means tell religious yarns if you are afraid of the dark, but don't bring them into scientific contexts, as though they had anything of value to offer. They don't. In fact, what they offer, as Jerry Coyne points out, is only a blurring of boundaries.
Religion does not respect boundaries. Like any other form of monolithism religion is quite prepared to mix private and public, empiricism with superstition, law with personal choice. [...] It is a danger to anything that requires critical thinking. There is no place for humility or even etiquette here, whether or not science can or cannot prove a negative. What science can and should say is that it has no need of this hypothesis. In fact, I would hazard the guess that if there is a problem about scientific literacy, this is related to the fact that, for many, religion provides the illusion of knowing already. Making it clear that religion is something private - as private as poetry and considerably less helpful - and that the only reliable ways of knowing involve critical rationality and empirical evidence, might help to separate things that, in public discourse, are too often conflated.
Gould was wrong about NOMA, but he had the right idea. Religion needs to be put in its place. It has no relation to science whatsoever, and, despite its claims to the contrary, no special moral authority. Once this is clearly understood, the religious are free to tell each other stories, if it helps them get through the night. They may even imagine, in private, that they are talking about real things, but there is no reason for others to believe this, and lots of reasons why others should insist, and insist again, that religions must know their limits, and that they should not be taken seriously when they try to speak with a public voice.
Personally, I think that MacDonald has pretty much nailed it. This is just why we can't give religious beliefs a free ride.