God’s work in removing separations is a major theme of the New Testament, especially Paul’s letter to the Ephesians. Previously, the Jews alone were God’s special people. Now, God welcomes and includes all Gentiles (non-Jews) who follow Jesus.
But now in Christ Jesus you [Gentiles] who once were far off have been brought near by the blood of Christ. For He himself is our peace, who has made us both one and has broken down in His flesh the dividing wall of hostility by abolishing the law of commandments expressed in ordinances, that He might create in himself one new man in place of the two, so making peace, and might reconcile us both to God in one body through the cross, thereby killing the hostility. And He came and preached peace to you who were far off and peace to those who were near. For through Him we both have access in one Spirit to the Father. So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God (Ephesians 2:13-19).
Christ’s cross reconciled us all to God in one body.
Ephesians 2 sets the stage for the seven “ones” of Ephesians 4. The one Lord, Jesus Christ, has broken down the dividing wall imposed by the Law of Moses. The Law’s rules (“commandments … in ordinances”) separated priestly Israelites from their fellow Israelites. Above all, those rules separated Israelites from Gentiles. Now, Christ’s sacrifice has removed the Law’s barrier. Now, Christ gathers all His people—Jews and Gentiles—into “one body” with “one Spirit” who gives them all equal access to one Father.