... why not practice religion - Christianity, Judaism, Hinduism or whatever - without pretending that it is a true account of the world: treat it, as it were, as artrather than science? That, essentially, is the non-realist position, espoused by Don Cupitt and others, and foreshadowed by Paul Tillich, and is where I am nowadays.
I've read a lot of the non-realist literature - Don Cupitt (a beautifully hand-written letter from whom I cherish) is a particularly interesting writer, I think; twenty-odd years ago David Hart was the chaplain at Loughborough University, not too far from me.
I've always found it fascinating, but AFAIC where the wheels come off is that it's a largely cerebral, intellectual approach to religion which is likely to be only ever of limited appeal. It won't catch on in a big way, so to speak. I have absolutely no argument with, and for that matter go quite a long way with, those who interpret religion non-realistically as a corpus of symbolic myth with "cash value" (as William James put it) insofar as it satisfies the intellect without outraging it as supernatural, personalistic literalism does. That's fine for some; but I suspect that a non-realist God is too much of an airy and bloodless abstraction for people - usually in fraught circumstances - who very much want there to be a realist, objective God out there who does typically goddy things. That's to say, I don't know how much mileage bereaved parents, or somebody facing their imminent end from cancer (for example), would get out of a non-realist God which is Ultimate Concern (Tillich, I think?) or whatever. For a lot of people Bertrand Russell's idea of God as cosmic older brother does seem to loom large, and the non-realists can't I think ever hope to compete with that. It's a little like the Sinclair C5 of theology - seems like a good idea, but it'll never catch on.