"This is why, for the new covenant apostles, Jew-Gentile unity is pivotal to the early church. It is about more than human relational harmony. Instead, it acknowledges that God's kingdom purposes are in Christ.
He is the last man and the true Israel, the bearer of the Spirit. A Jewish person who clings to the tribal markings of the old covenant acts as though the eschaton has not arrived, as though one were still waiting for the promised seed. Both Jews and Gentiles must instead see their identities not in themselves or in the flesh but in Jesus Christ and in him alone. Jesus is the descendant of Abraham, the one who deserves the throne of David. He is the obedient Israel who inherits the blessings of the Mosaic covenant. He is the propitiation of God's wrath. He is the firstborn from the dead, the resurrection and the life.
Those who are in Christ - whether Jew or Gentile - receive with him all the eschatological blessings that are due to him. In him, they are all, whether Jew or Gentiles, sons of God - not only in terms of relationship with the Father but also in terms of promised inheritance (Rom. 8:12-17). In Christ, they all - whether Jew or Gentile - are sons of Abraham, the true circumcision, the holy nation, and the household and commonwealth of God (Gal. 3:23-4:7; Eph. 2-3; Col 2:6-15; 3:3-11; 1 Pet. 2:9-10)."
Russell Moore, "Personal and Cosmic Eschatology," in A Theology for the Church,