A few weeks ago, I posted some thoughts about how the pattern of realisation of the New Covenant in Jeremiah 31 might be reflected in New Testament texts about how the Gentiles have been grafted into an already-renewed Israel. One of the places I think this is seen is in Ephesians 1 and 2. Many commentaries make little of Paul’s alternating use of ‘we’ and ‘you’ in this passage, but they are missing something important. John Stott picks up the significance in his work, but of all the commentaries on Ephesians, Markus Barth’s volume is one of the best on this. Here’s an excerpt of what he writes:
The verses 1:11-13 contain distinct statements made about us ("we") and about "you"..…
In decisive passages of Ephesians…the change between "we" and "you," "our" and "your," indicates something other than…an appeal to a common Christian creed, or a cavalier, unnecessary, and meaningless change of diction: as observed earlier, those addressed in Ephesians are all of Gentile origin. They have been "apart from the Messiah, excluded from the citizenship of Israel, strangers to the covenants . . . bare of hope and without God" (2:12). These formerly hopeless people are distinct from other men who have equally been "under the wrath [of God]" (2:3), but were privileged to be the "first to set" their "hope upon the Messiah" (1:12). While the latter call themselves "The Circumcision" because of a "handmade operation," the former are called "The Uncircumcision" (2:11).
In 2:17 (cf. 13), one of these two groups is called "those who are far," the other, "those near." 2:19 speaks of recently naturalized citizens, or newly adopted children who are now among the saints as members of God's household. Five times the first group is called "the nations" or I "the Gentiles"; in 2:12 the second group is explicitly identified as "Israel." It is emphatically asserted that Gentiles have now been made fellow heirs, fellow members, fellow beneficiaries in an heirdom, a body, and a promise that were established already before any Gentiles were given access to it (l:18c; 2:19; 3:6). Gentiles now partake of Israel's privileges and possess the same rights and titles as were formerly reserved for the Jews only….
Just as in Rom 1:16, so also in Ephesians, Paul calls election and salvation by grace events that concern "the Jew first and [also] the Greek."
Markus Barth, Ephesians: Introduction, Translation, and Commentary on Chapters 1-3 (Anchor Bible, Vol. 34), 130-1, emphasis added.