Having talked about the role of Jesus in bringing all to God (vv.11-13) Paul now builds on this to have his readers see the unity available in Christ.
There is no longer an ‘us and them’ mentality among the people of God: Paul talks now of Jesus having made ‘us’ both one (Jew and Gentile). He did this through breaking down in his flesh the dividing wall of hostility by abolishing the law of commandments expressed in ordinances. Simply, Jesus fulfilled the righteous requirements of the law that separated Jews (those who sought to keep it) and Gentiles (those who did not). The law and its promise of righteousness-earnt is no longer a dividing wall between people groups.
There are no second-class citizens in the Kingdom of God. We all have access in one Spirit to the Father. We are all, regardless of ethnicity or heritage, fellow citizens with the saints and members of the household of God. This household, we read, was built on the foundation of those closest to the Lord Himself, the apostles and prophets, but is held together, joined, stabilised, and is totally reliant on Christ Jesus (vv.20-23).
For you and for me this means that no matter who we are, no matter where are from, no matter our religious upbringing (or lack of), that we have the opportunity to be built together into a dwelling place for God by the Spirit. We have the opportunity, through the life, death, and resurrection of Jesus, to be first class citizens in the Kingdom of God. We have this opportunity only through Christ Jesus.