Andrew - I’m only commenting on your summary, not the discussion as a whole. Much of your interpretation of scripture hangs on your 4th point - which contains a mixture, as I see it, of things which scripture affirms, and things it does not.

Your emphasis on the recovery of the promise to Abraham, through Christ, contrasts with  the NT presentation of Christ as the fulfilment of that promise. This is a crucial difference, as it also affects creation, and the message which is to be proclaimed worldwide. 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. Christ is the means, in himself, of how creation is to be blessed and reclaimed.

How does this rearrangement of things affect the message to be proclaimed and life to be lived? In your version, Christ becomes secondary to the purpose. In the NT, Christ is the purpose. Everything we have, and everything which is to happen to creation, is to be found only in him. The focus is not ‘the promise to Abraham’ of a renewed creation, but the content of that promise, which is Christ, and how it was to come about, which is exclusively in relation to him.

Your 5th point reflects your view of NT faith - which for you is not a template for faith beyond the immediate historic context. This is a huge contrast with what most take to be true - no matter how skilfully and energetically you argue it. It’s not surprising that you see in the post-Constantinian political and ecclesiastical arrangements the potential for an interpretation of the faith which bears out your basic assumptions. But are your views anywhere substantiated by the views of early contemporary theologians - mainstream or otherwise? I suspect they would be horrified if it was suggested that they were providing an interpretion of the NT which denied its authority for believers beyond the immediate 1st century context.

In your 5th and 6th points, I’ve argued before, and argue again, that 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. On the other hand, there have been recovery and renewal movements which attempted to retain the simplicity and purity of the original faith from the very earliest times, which were continuous throughout the period to the present day, were widespread (throughout Europe) and historically extensive. In fact the recovery movements cut across boundaries - they existed both within and outside the ‘official’ church.

Within and outside the ‘official’ church, what criteria should we be looking at to assess the integrity of the faith? I suggest: 1. an overriding devotion to Christ, as the key to everything believed, and 2. evidence of the character of Christ in the lives and lifestyle of those who believe. Such qualities cut across ecclesiastical boundaries, where authority is vested in the particular truths or organisational procedures a church may adopt, be it apostolic succession, nature of the priesthood, bishops, doctrinal differences concerning the eucharist, baptism, Spirit-reception, or whatever.

Today, a healthy worldwide pluralism of faith rests alongside a bigotry and  denigration of alternative expressions of faith which is astonishing and regrettable - mainly because of boundaries being set where they were never intended to be.  A healthy faith rests on an inclusive attitude towards others, provided that there is clear evidence of overriding devotion to Christ, and evidence of the fruits of Christ’s character in the lives of those who follow him.