In Romans 9, Paul expressed anguish because many post-exile descendents of the tribes of Judah, Benjamin and some from Levi (collectively referred to as Jews) had rejected Jesus. Some even took part in killing the Messiah. The overwhelming opposition of Jewish leadership toward Jesus at that time forced Paul to answer the big question on his readers minds. Had the word of God to Abraham failed?

Answer: No. The word of God to Abraham had not failed. Paul explains why.

“But it is not as though the word of God has failed. For not all who are descended from Israel belong to Israel [literally: “Not for all who [are] of Israel [are] these Israel”], and not all are children of Abraham because they are his offspring, but “Through Isaac shall your offspring be named.” This means that it is not the children of the flesh [all of Abraham’s genetic lineage through all his sons] who are the children of God, but the children of the promise are counted as offspring.” (Romans 9:6-8)

Paul was stating that matching DNA does not cause one to belong to God’s chosen people called Israel. Rather, there is another way to identify the group called Israel that would be counted as Abraham’s offspring and “children of the promise”.

Who are “the children of the promise” that are counted as offspring of Abraham?

This is clear from Galatians.

“Know then that it is those of faith who are the sons of Abraham. And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham, saying, “In you shall all the nations be blessed.” So then, those who are of faith are blessed along with Abraham, the man of faith.” (Galatians 3:7-9)

“Now the promises were made to Abraham and to his offspring. It does not say, “And to offsprings,” referring to many, but referring to one, “And to your offspring,” who is Christ.” (Galatians 3:16)

“Through Isaac shall your offspring be named” meant that Jesus would come through the direct lineage of Isaac, a promise that was fulfilled 42 generations later. (Matthew 1:1-17)

We now see why there was so much emphasis on Abrahams faith. “It is those of faith who are the sons of Abraham”. The gospel to Abraham was “In you shall all the nations be blessed.” All the nations are blessed because, through faith in Christ, anyone can share in the promises to Abraham, regardless of DNA lineage. 

“so that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we might receive the promised Spirit through faith.” (Galatians 3:14)

Faith brings the blessing of Abraham to the Gentiles, makes one “Abraham’s offspring” and “blessed along with Abraham” and an heir “according to promise”. All those of faith are one in Christ Jesus.

“For as many of you as were baptized into Christ have put on Christ. There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus. And if you are Christ’s, then you are Abraham’s offspring, heirs according to promise.” (Galatians 3:27-29)

It isn’t being Jewish that makes one part of God’s Israel. It’s being a new creation.

“For neither circumcision counts for anything, nor uncircumcision, but a new creation. And as for all who walk by this rule, peace and mercy be upon them, and upon the Israel of God.” (Galatians 6:15-16)

It isn’t blood line either. Rather, it’s a gift of grace given to all who receive Jesus and believe.

“But to all who did receive him, who believed in his name, he gave the right to become children of God, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God.” (John 1:12-13)

Once we know who Abraham’s offspring really are, the Old Testament explodes with significance for those of faith called the offspring of Abraham or Israel. 

“But you, Israel, my servant, Jacob, whom I have chosen, the offspring of Abraham, my friend; you whom I took from the ends of the earth, and called from its farthest corners, saying to you, “You are my servant, I have chosen you and not cast you off”; (Isaiah 41:8-9)

“In the Lord all the offspring of Israel shall be justified and shall glory.” (Isaiah 45:25)

God has never defaulted on his promises to the the children of the promise. They are “his people“. They are redeemed. They are the “Israel of God”, “Abraham’s offspring, heirs according to promise.”