We are not encouraged to see the period of Israel under the Law as a parenthesis, with Christ facilitating a return to the emphasis of an earlier phase, but to see Christ as the very meaning and fulfilment of the promises to Abraham and Israel.

Peter, the question I would ask here is this: Under what circumstances do the promises to Israel that are fulfilled in Jesus arise? I would hazard a guess that pretty much all the prophecies that are seen in the New Testament as finding fulfilment in the Jesus story relate to the theme of judgment and restoration. In other words, the messianic hope emerges as a response to the failure of Law-based Judaism and the prospect of ensuing destruction. Christ becomes necessary (you won’t like me putting it that way) because the Law eventually condemned the people to destruction. So national Israel inevitably becomes a parenthesis.

In the NT, Christ is the purpose.

No, if Christ is the saviour, the purpose must be defined in terms of what is saved, surely? God so loved the world that he gave his only begotten Son. The purpose is the actualization of God’s love for the world. The means is the giving of the Son. The purpose has to do with the effective missional existence of a people for God’s own possession in the world; Christ is the means by which that purpose is fulfilled. Isn’t this Paul’s argument in Ephesians 1: the whole story about Jesus, right up to the statement about all things being put under his feet, is ‘for the church, which is his body, the fulness of him who fills all in all’?

Your 5th point reflects your view of NT faith - which for you is not a template for faith beyond the immediate historic context. 

I have to say I still see nothing intrinsically wrong - as a matter of historical interpretation - with the argument that the New Testament understanding of ‘faith’ is fundamentally shaped by the eschatological narrative that is everywhere presupposed, that this eschatological narrative is historically contingent (it has to do with the restoration of the people of God and the enthronement of Christ as king in place of Caesar), and that this contingency should therefore be taken into account when we try to explain what faith should mean for us, when we are not part of that eschatological narrative.

…Christendom is a poor concept to apply to the faith since early post-apostolic times, since it is a term unheard of in the NT itself, and suggests concepts which are nowhere hinted at in the NT, even as possibilities, beyond the immediate 1st century period.

I agree. The New Testament does not really describe Christendom - I don’t think the New Testament sees much beyond the victory over Rome. But the church unquestionably modelled itself on empire and that is not described in the New Testament. So either we dismiss the Christendom church as an unholy departure from the New Testament and argue that it is only in the dissenting movements that the true faith survived, or we ask whether in the light of scripture as a whole there is some way of making sense of the church’s instinct to become a globally organized polity.

The evangelical simplicity of your formula for integrity of faith is very attractive and in many respects I would thoroughly endorse it, but I don’t think it provides an adequate hermeneutic of scripture.