But it is not as though the word of God has failed. For not all who are descended from Israel belong to 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 who are the children of God, but the children of the promise are counted as offspring.
Many people believe that because God decided years ago to show himself through one nation (Israel), that this is still his chosen nation. I am not so sure all I believe regarding this subject. When I read through chapters 9-11, I see that Paul is working very hard to say that God's election is specific based upon his sovereign choice alone. I see that Paul desires for his kinsmen (Israel) to believe upon Jesus as their Lord and Redeemer. I see that this choice is not so much based upon bloodlines, but upon a remnant of individuals whom either believe, or will believe upon Christ. Later on in the chapter, we see that God chose to set his saving love upon Jacob, and his damning hate upon Esau. He chose to do this while both children were in their mother's womb; before either one of them did anything good or bad. Hard truth to swallow? A bit yes; but what do you do, this is what the Scripture says.
Not all Israel is Israel, says our text. Which also would seem to mean that not all Gentiles are Gentiles. It is not the children of the flesh (the circumcised) who are the children of God, but the children of the promise. The way I understand this subject is that there has always been a line of believers throughout the Old Testament who believed by faith; who believed the promise of a coming Messiah. We speak the good news to anyone who will listen because God is able to graft any branch (wild or natural) into his olive tree. When this branch is grafted in, he or she becomes a true Israelite; an Israelite indeed. Does God still have a plan for the nation of Israel as a whole? Maybe. When we read up to chapter 11, it does seem to suggest that the hardening that God has done in their hearts will be removed. It may be removed in full, or in part; I am not really sure. What I do know is that God has it all figured out and determined to perfection. He calls me and you to trust him, and speak of his son Jesus to anyone who will listen.