Is religiously inspired morality a crane or a skyhook? That is to ask: when a religious person attempts to build their character in a particular direction, are they building on pre-existent morality, or hoiking down something from God or the bible? I would claim it is self-evident that they are building on pre-existent moral urges and predispositions; more, that each successive act of willpower or moral exertion builds on the ones before. To this extent they are using, in Dan Dennett’s terminology, cranes. They are building themselves, step by step, on previously built foundations, using techniques that have worked before. What’s more, I don’t see how that morality could work otherwise. It is possible that some charismatics disagree with me and suppose that a single intervention from above could change everything. I think that the Catholic doctrine of grace might be interpreted that way, though I don’t know enough about that. But in general, my experience of Catholics is that they expect grace to build on nature, in the phrase.
The point of this is that it suits both sides often to think of religious belief is working like viral DNA: it takes over the pre-existing character and moral judgement and zombifies it. Yet, while we can think of people who are like that for a while, how long do they last? As Eileen Barker’s work showed, most Moonies grow up. So do most Christians of my acquaintance, and most atheists, too. But if you naturalise religion in this way, you take away a lot of of the fun from atheism. The atheist, too, wants to struggle with principalities and powers, or at least with skyhooks and memes.
I know this isn’t widely accepted, but that only shows I’m right: it seems to me that differences in temperament are much more profound than differences in creed: that how you believe is more important than what you believe.