The PROMISES in the Old Testament Scriptures that were given to Israel were actually given to the ISRAEL OF GOD. This is the spiritual Israel or the “TRUE ISRAEL.” It is for Jesus Christ and His people. These are called Christians. They are those who are in Christ by faith, the church, the body of Christ, made up of believing Jews and believing Gentiles.
“8 That is, those who are the children of the flesh (physical Israel), these are NOT the children of God; but the children of the promise are counted as the seed.” (Rom. 9:8).
The Old Covenant Jewish religious system was dependent on the Law. This only brought a curse upon the physical Jews. Only those who are of faith are TRUE SONS of Abraham (Gal. 3:7). Those who are of faith are blessed with believing Abraham (Gal. 3:9). No one is justified by the Old Covenant Law, for “the just shall live by faith.” The Law involves works, which produce a curse because no one can fully obey the works of the law (Gal. 3:10-12).
Christ has redeemed every faithful believer from the curse of the Law, having become a curse for us, that the BLESSING OF ABRAHAM might come upon the Gentiles IN CHRIST JESUS, that we might receive the PROMISE of the Spirit through faith (Gal. 3:13-14). The PROMISES were made to Abraham and his Seed through Isaac. “In Isaac your seed shall be called.” It does not say “seeds” as of many, but as of one Seed, who is Christ (Gal. 3:16; Gen. 21:12).
The Scripture has confined all under sin. There is no exception. All have sinned and fallen short of the glory of God. As a result the PROMISE by faith in Jesus Christ has been given to all those who BELIEVE (Gal. 3:22). All TRUE SPIRITUAL JEWS are SONS OF GOD through faith in Christ Jesus. There is NO LONGER JEW OR GENTILE, but all are one in Christ Jesus (Gal. 3:26-28). All believers in Christ, belong to Him, and are therefore Abraham’s spiritual seed, AND HEIRS TO THE PROMISE of eternal life (Gal. 3:29).
“29And if you are Christ’s, then you are Abraham’s seed, and HEIRS ACCORDING TO THE PROMISE.” (Gal 3:29).
“13For THE PROMISE that he would be the HEIR OF THE WORLD was not to Abraham or to his seed THROUGH THE LAW, BUT THROUGH THE RIGHTEOUSNESS OF FAITHS.” (Rom. 4:13).
[For a more in-depth study see eschatology “Study Series 11 on Romans 11”]