In Romans 9-11, Paul’s emphasis concerning the salvation of the Jews is that it is a remnant according to the election of grace and not according to race, or ethnic privilege.
Paul actually covers the entire history of the Jewish people in these 3 chapters showing that election according to grace has been God’s plan from the beginning.
In 9:6-13 he begins with the promise given to Abraham and shows how that through the calling of Abraham and his descendants, God’s plan of election according to grace is revealed.
The succession of the promise was from Abraham to Isaac, not Ishmael. It continued from Isaac to Jacob, not Esau. Though they were the physical descendants of Abraham even as Isaac and Jacob were, Ishmael and Esau were not included in the covenant of promise – the election according to grace.
In Isaac and Jacob, God reveals that the election according to grace is based on (1) promise and (2) grace.
9 For this is THE WORD OF PROMISE, at this time will I come, and Sarah shall have a son.
10 And not only this; but when Rebecca also had conceived by one, even by our father Isaac;
11 (For the children BEING NOT YET BORN, neither having done any good or evil, THAT THE PURPOSE OF GOD ACCORDING TO ELECTION might stand, NOT OF WORKS, but of him that calleth;)
12 It was said unto her, The elder shall serve the younger.
Isaac and Jacob represent the promise and that which is born of the Spirit, in contrast to Ishmael and Esau who represent the flesh. Ishmael was born through Abraham’s own effort, and Esau did not esteem the blessing.
It is therefore, a fallacy, to think that all of Abraham’s physical descendants would be heirs to the promise. Consider Romans 9:6-8:
Not as though the word of God hath taken none effect. For THEY ARE NOT ALL ISRAEL, WHICH ARE OF ISRAEL: Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called. That is, they which are THE CHILDREN OF THE FLESH, these are not the children of God: but THE CHILDREN OF THE PROMISE are counted for the seed (Romans 9:6-8).
Paul makes a specific distinction between the Jews. He refers to some as “the children of the flesh” and to the others as “the children of the promise.” Thus echoing what he has previously said in chapter 4: “if THEY WHICH ARE OF THE LAW be heirs, faith is made void, and THE PROMISE made of none effect…” (Romans 4:14).
Those which are OF THE LAW, mentioned in 4:13 (above), is a reference to the same Jews of whom Paul refers in chapter 9 as the children of the flesh. Paul says unequivocally, THESE ARE NOT the children of God, and that is why he says: “they are not all Israel, which are of Israel.”
God’s true Israel consists of those who are the descendants of Abraham according to the promise, and the promise given to Abraham was that he would be the father of ALL THAT BELIEVE (Romans 4:11). Therefore it is those who are of faith who are the children of promise.
Even though they are of Israel, not all Jews are Israel according to the promise because of their unbelief. They, like unbelieving Gentiles, stumble over the message of the gospel of Jesus Christ.
In Galatians 4:28, Paul speaking to the Gentiles who have faith in Jesus, says; “Now we, brethren, as Isaac was, are THE CHILDREN OF PROMISE.” In Galatians, Paul is countering the influence of the Judaizers who were attempting to make Jewish converts of the Gentiles by preaching circumcision and the Law.
Paul tells the Galatians: Christ hath redeemed us from the curse of the law, being made a curse for us: for it is written, Cursed is every one that hangeth on a tree: That the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive THE PROMISE OF THE SPIRIT THROUGH FAITH (Galatians 3:13-14).
The promise of the Spirit refers to the promise God gave to Abraham.
In Galatians 3:8 Paul says, “…the scripture, foreseeing that God would justify the heathen through faith, preached before THE GOSPEL unto Abraham, saying, in thee shall ALL NATIONS be blessed.”
God’s promise to Abraham, which Abraham believed and was justified, was the promise that would bless ALL NATIONS, and Paul declares that this is also the gospel!
In Romans 4, Paul refers to THE PROMISE as Abraham becoming THE HEIR OF THE WORLD: For the promise, that he should be the “heir of the world,” was not to Abraham, or to his seed, through the law, but through the righteousness of faith (Romans 4:13).
Notice that Paul makes a distinction between “the Law” and the “righteousness of faith” with regards to this promise. God’s promise wasn’t to Abraham alone; it was to Abraham and his seed, namely, Christ.
Later in Galatians 3 Paul says: For ye are all the children of God by faith in Christ Jesus. For as many of you as have been baptized into Christ have put on Christ. There is neither JEW nor GREEK, there is neither bond nor free, there is neither male nor female: for ye are all ONE in Christ Jesus. And if ye be Christ’s, then are ye ABRAHAM’S SEED, AND HEIRS ACCORDING TO THE PROMISE (Galatians 3:26-29).