As I read the prophets, I am getting a picture of a Millennial Kingdom in which the world is organized into spheres with Messiah at the center.
Sphere 1: Messiah Yeshua
Sphere 2: Kohanim
Sphere 3: Levites
Sphere 4: Natural Israel
Sphere 5: Naturalized Israel (The Mixed Multitude)
Sphere 6: Believing Nations
Sphere 7: Unbelieving Nations
Remember that Paul's statement about Jew & Gentile, male & female, slave & free, was made only in the context of salvation. It was never meant to be applied more broadly than that.
This is probably not an accurate picture, but I suspect it's in the neighborhood.