In the context, he seems to me to be saying that Christians are called into a community from no single pre-existing entity; the Christian community was not before it was called into being, and no other characterization holds priority over our identity as Christians.

Relative to Judaism, I suspect that Williams might identify the call to Abram as a constitution ex nihilo of the people of Israel; before Abram responded to the divine voice, there was not “a people” of God. After Abram and Sarai set out for the land that he had been promised, the extended family unit looks like an inaugural version of “God’s people.”

But he may also have allowed the Christian theological theme of ex nihilo to overdetermine his remarks relative to Judaism; I, in turn, would be intrigued to hear how Peter Ochs reponds to Williams’s hermeneutics.

In a nutshell, no one would have a choice about a Divinity, if he-she is really all he-she is cracked up to be, one way or another, like it or not, so why dribble all over ourselves about such a Being? I only hope a sense of humor is included, or I’m out. Are we not playing with words?

How that fits with other Christians’ beliefs is not a question I’m fit to begin to address.

Good Lord, no. Absolutely not.

Before going further I should say that I’m in an odd position here, partly because I’m strictly an ex-Christian, but mainly because the form of Christianity I no longer believe in (but still sympathise with) is quite big on the discontinuity between old and the new covenants. So I was just as uncomfortable as you with Williams’ repeated stress on the continuity between the two, albeit for the opposite reason. But I think he makes a very good case for continuity; if it is wrong it’s wrong in a way I haven’t got to the bottom of.

It certainly isn’t wrong in the way you suggest. For believers, the Christian church – the ‘body of Christ’ – is precisely a community which extends over space and time; it’s instantiated or made physically present by the religious service, but it’s certainly not created. Here’s C.S. Lewis from The Screwtape Letters (supposedly written by a senior devil to a junior):

“One of our great allies at present is the Church itself. Do not misunderstand me. I do not mean the Church as we see her spread but through all time and space and rooted in eternity, terrible as an army with banners. That, I confess, is a spectacle which makes our boldest tempters uneasy. But fortunately it is quite invisible to these humans. All your patient sees is the half-finished, sham Gothic erection on the new building estate. … When he gets to his pew and looks round him he sees just that selection of his neighbours whom he has hitherto avoided. You want to lean pretty heavily on those neighbours. Make his mind flit to and fro between an expression like ‘the body of Christ’ and the actual faces in the next pew.”

And so on. The punters in the pews are ‘the body of Christ’, but they don’t constitute it or create it from nothing.

I can see I’m going to have to re-read Williams’ lecture, to work out what he was going on about. I blogged on it here, incidentally.