They Are to Remember that They Were Once Excluded From Israel and the Promises But Are Now Made One With the True Israel; They Are Now the People of God (2:11-3:12)
Paul here goes on to point out that the ordinances of the Law of Sinai (the whole sacrificial system and all that pertained to it), which were a cause of separation as they were what made Israel distinctive, have now been done away through His cross, which has superseded all offerings and sacrifices, and the result is that all can now be received within that covenant, and within the Abrahamic covenant of promise which offered blessing to the nations (see Galatians 3; Genesis 12:3), and enjoy the same relationship with God and with each other as was dispensed though that covenant. He points out the disadvantages that they had endured while separated, not so much because they had necessarily been concerned about those disadvantages but in order to demonstrate that it was those advantages that they had now gained by having the separation removed. He very strongly emphasises that the two (Jews and Gentiles) have been made one within His covenant. There is now one new Israel, one church, and all who believe are a part of it.
It should be noted that the idea is not that the Law has been abolished, but that it has rather been fulfilled in Christ (Matthew 5:17-18). That is why those who are in Christ will fulfil the Law by being filled with His love, not disregard it (Galatians 5:13-14).