Against the major role assigned to Rome in your understanding of the biblical narrative I would elevate the issue of continuity of the old covenant. The first New Testament eschatological event, in my covenantal understanding of the biblical narrative, is the end/fulfillment of the old covenant. (The yet-to-come eschatological event is the end/fulfillment of the new.) This "event" lasts from the rejection of God’s annointed one by Israel and concludes with the destruction of the temple and the end of Israel as a theocratic political nation.

According to my understanding, it is a mistake to see significant "continuity" in the people of God. Under the old covenant, the people of God really were constituted in primarily racial terms; from an old covenant perspective, the time when the people of God would be from all nations was eschatology. (It is also a mistake to look for continuity in purpose.) The narrative moves forward, but it moves on a different level than before—just as the Sinai covenant was itself a significant development in the broader Abrahamic narrative. I believe that even had Israel been true to the Messiah en masse, the old covenant (along with its theocracy and temply system) was destined to be be set aside (in terms of plot development) to make way for the church.

Further, it is characteristic of the church (as opposed to Israel) that our purpose is evangelistic. This is commanded in Jesus’ parting words, reported in Acts, modeled by Paul, and envisioned fulfilled in John’s apocalypse (where a great crowd of people that nobody can count is gathered around God’s throne, from every people group—that is the narrative conclusion).

In contrast with the old covenant, the new covenant is less political and more spiritual and individualistic. However, I believe a narrative approach to theology corrects a post-apostolic hellenization of theology. The dominance of platonism (with its dualism between ideal and form, between matter and spirit, between faith and action) is what is weakened by this more holistic narrative reading.