For he is our peace; in his flesh he has made both groups into one and has broken down the dividing wall, that is, the hostility between us. (Eph 2:14)
The second half of Ephesians 2 deals with two topics of highest importance to Paul. First, there is a discussion of the salvation of the Gentiles (vv. 11-16), building on the previous description of salvation by grace through faith (vv. 1-10). Paul argues that, although they were once outsiders with respect to the long history of God’s dealings with Israel, through Christ this longstanding spiritual divide has been erased.
The gospel is for everyone because, by dying for all, Jesus has torn down the walls that divide us from each other. Since everyone is saved by grace through faith (2:8), everyone may come near to God through Christ. If we have been reconciled to God, we must accept that we have also been reconciled to each other and are growing together into one holy temple, the church.
Second, Paul reflects on the nature of the church (vv. 17-22). Having brought Jew and Gentile together in salvation, both are now citizens of God’s kingdom and members of God’s household. They are being built into a holy temple-a dwelling place of the Holy Spirit‚ with Jesus himself as the cornerstone.