The argument runs something like this….
The church began as a movement within first century Judaism. Like any other historical movement, its character and purpose were shaped by its historical circumstances. It was a product of its time and place. It was part of an ancient story.
The church presented itself, in the first place, as the solution to a concrete Jewish problem: how would the covenant people survive the foreseen disaster of the war against Rome and the destruction of Jerusalem and the temple? It then discovered that the solution to this problem—the way of Jesus—opened up a further quite stunning horizon. The judgment and salvation of Israel would lead eventually to the judgment and salvation of the Greek-Roman world.
This two-stage argument about the future of God and his people was explained by reference to the Jewish scriptures, as the climax to a complex but persistent narrative that could be traced back through the historical experience of foreign oppression and exile to the promise of YHWH to David that his throne would be established forever (2 Sam. 7:16).