To Robin: I think the central problem is that religion makes claims, not arguments, and then changes its claims when they become untenable. But since claims are all religion has got, it doesn't really have an essence to keep constant during this process. Perhaps one could argue that the method of making claims is what the essence is, like the scholarly or lawyerly method/mentality. This is hard for me to swallow, though, since the religious method of claiming is just "because God says so," which doesn't strike me as a permissible essence. Similarly, religious people like to talk about "faith" as the essence, but this is circular.