A primary problem with your broader proposal is that it tosses us into an even later period, with greater distance from key historical events and still fails in the attempt to find something that would resemble a "people of God" on which we could safely model ourselves.

I take your point, but:

1. Perhaps that’s just indicative of the fact that we don’t know our church history well enough - that we’re too much focused on the events of the New Testament period. I think it might be a really instructive exercise to gain a better grasp of what was happening when Christianity shifted from persecuted minority to imperial religion. Why shouldn’t we regard this as an event of similar importance to the exodus or the exile or the destruction of Jerusalem or the Reformation?

2. I think that this later event (the victory over Rome and the emergence of Christendom) is intimately connected by eschatological narrative to the events of the New Testament. It is simply again a matter of historical myopia that we have overlooked that.

3. I’m not suggesting that we model ourselves on the Christendom people of God. It seems to me that we need to draw our identity from the whole biblical narrative, beginning crucially with the renewal of creation with the call of Abraham. It helps to understand how Israel organized itself, how it sought to maintain obedience, how it shaped its life, how it lived in the land, how it interpreted events - and how that whole experience was reinterpreted by Jesus. And then we ask how that narrative trajectory takes the people of God into a difficult future, when its very existence is threatened by the power of Rome. And so on…