Not however as though the word of God had failed; for not all [are] Israel which [are] of Israel;
Paul has just poured out his grief over his own nation, listing every privilege God gave them — and yet they stand outside the blessing. If the people God chose have refused their Messiah, has His promise collapsed?
The verse answers a charge Paul's teaching had provoked:
Paul had been teaching that all, whether Jew or Gentile, come into blessing on the ground of sovereign grace. At once the Jew raises the objection that this teaching denies the promises which come to them on the ground of natural descent. The apostle answers that not all who are of Israel by natural descent are the true Israel of God — the Israel God made the promises to. He then turns to Scripture to prove his point.
Push the principle of bloodline, and it proves far more than any Jew wanted:
Their objection assumed that God had to bless the whole race descended from Abraham. But that would open the promises to the Ishmaelites as well. Not so, cries the Jew: the promise runs only through Isaac. Then, the apostle could reply, natural descent is an unsound principle... So to shut out the Ishmaelites, they must themselves fall back on the promise tied to the line of Isaac. Promise decides, then, not flesh... Descent by birth alone secures no inward blessing. "The Israelite indeed, in whom there is no deceit" is more than one of Jacob's descendants: not all who are descended from Israel belong to Israel.
The examples Paul reaches for are Isaac over Ishmael and Jacob over Esau — God's own past choices. That makes the Jewish complaint self-defeating:
Of all people, Israel could least afford to quarrel with God's sovereignty. Again and again He had used it in their favour... God made a sovereign choice in regard to the sons of both Abraham and Isaac. He chose Isaac and Jacob, and set aside Ishmael and Esau. Anyone objecting to God making a choice would have to wipe out every distinction between themselves and the Ishmaelites and Edomites. They would not consider that for a moment. So God was only continuing what He had already done. Not all who were of Israel by natural descent were the true Israel of God.
The name Israel was first given to one man, and how he received it explains the distinction:
God's reckoning is a spiritual one. Natural birth cannot presume to claim blessings that God gives for spiritual reasons. Jacob was named Israel only when his flesh was touched and left shriveled. How then can natural Israel claim to be "Israelites indeed"? Their flesh is far from shriveled — it is the very thing they boast in. That is Jacob, not Israel.
The true Israel is smaller than the visible nation. So Paul could hold God's thoughts for them even when the nation looked lost:
Far from cancelling Israel's future, this verse is what secures it:
This explains that verse, "all Israel will be saved." Remembering that "not all who are descended from Israel belong to Israel," we see here the unreal cut off. But God lets none of the true seed, the true children, perish; they are all saved. They are truly Israelites. The national adoption as sons, the glory, the covenants, the giving of the law, the service, and the promises are all theirs.
- Objection — Does grace for all cancel Israel's promises? Paul answers that the promises never rested on natural descent.
- Principle — Promise, not flesh, decides. Blood alone secures no inward blessing, and a true Israelite is more than one of Jacob's descendants.
- Proof — God chose Isaac over Ishmael and Jacob over Esau. To protest His choosing, Israel would have to admit the Ishmaelites and Edomites as equals.
- Remnant — As in Elijah's day, God keeps a reserved number. So His word stands even when the nation as a whole refuses to believe.
- Promise kept — God's calling marks out the true seed, not birth. So nothing promised to Israel is lost: the unreal are cut off, and God saves every true child.
nor because they are seed of Abraham [are] all children but, In Isaac shall a seed be called to thee.
Paul has just voiced his grief over Israel, and now faces the obvious question: has God's word to the nation failed? His answer comes from Israel's own family tree — from Abraham's two sons, Ishmael and Isaac.
The Jewish claim was that descent from Abraham guaranteed the promises. Paul takes that principle and follows it to a conclusion no one would accept. (The writers quote an older wording, "In Isaac shall your seed be called." The ESV reads, "Through Isaac shall your offspring be named.")
You claim to be children — and the only children of promise — because you are Abraham's natural seed. But it is written, "In Isaac shall your seed be called." If you take it as descent according to the flesh, you must let in the Ishmaelites. The Jew would answer, "Ah, that was a slave — not a true child of promise." Still it showed that the children according to the flesh are not the children of God, but the children of promise.
The objector himself has to reach for the promise to keep the Ishmaelites out — and by doing so he abandons his own case.
Not so, cries the Jew: the promise is only in the line of Isaac. Then, might the apostle reply, natural descent is an unsound principle... They themselves therefore, to exclude the Ishmaelites, must fall back on the promise tied to the line of Isaac. Promise therefore, not flesh, decides.
The difference between the two sons is where each came from. One came by the will of the flesh; the other came because God had spoken.
The flesh can produce nothing except what is flesh... God knew its character from the beginning. He knew it was a corrupt source and therefore a source of nothing but corruption. So He passed by Ishmael, the child of the flesh. His election rested on Isaac, the child of promise — the son whose origin lay in the resurrection power of God, expressed in His promise of earlier years.
God held back Isaac's birth until nature could give nothing.
Ishmael was no true heir of promise, for his birth was at the will and in the power of the flesh. In natural order he was Abraham's heir. But natural inheritance can never take in the promises of God. The word of promise must create its own fit object, according to the power of God. So Isaac's birth waits until the force of nature is spent, so that his birth might be of God.
The verse turns on a verb: the seed is called. Even the objector has to appeal to the promise about Isaac, and that hands the decision to God.
They themselves therefore, to exclude the Ishmaelites, must fall back on the promise tied to the line of Isaac. Promise therefore, not flesh, decides... Fleshly descent alone secures no inward blessing... God must be left free; and He is pleased to call Isaac, not Ishmael in the same way.
The same principle that shuts out mere descent keeps a door open. The argument then runs on to Jacob and Esau, and back to Israel at Mount Sinai.
Sovereignty therefore is the only source of hope for Israel. The chapter reasons this out further and applies it to Jacob, shutting out Esau — though they had the same mother as well as father, and were even twins. But the same sovereignty of God was Israel's only resource at Mount Sinai, when everything else had ended in ruin for the people as a whole through their worship of the golden calf... Driven from the ground of law, as well as of lineal descent, what could they fall back on? On the sovereign mercy of God.
So the promise has not shrunk. It rests on a believing remnant inside the nation, not on the nation as a whole.
The unbelieving mass of the nation are children of Abraham according to the flesh. But only the believing remnant are the true seed according to promise. Still, even the children according to the flesh would be great upon the earth.
The way Isaac came into the world is the pattern for everyone who belongs to Christ.
In Isaac we see that family who are "born not of blood nor of the will of the flesh nor of the will of man, but of God," and who stand in liberty. As the apostle says, "Now we, brothers, as Isaac was, are the children of promise." We are Abraham's seed — so many Isaacs, children of the free woman, or in the adoption, if we are Christ's.
- Promise, not pedigree. If birth from Abraham settled it, Ishmael's descendants would have an equal claim. No one allowed that, so descent cannot be the rule.
- Promise creates its own heir. Isaac came only when natural strength was gone. His life traced back to God's word, not to human power.
- Promise means calling. God names the seed; a family line does not. He was free to call Isaac and not Ishmael.
- Promise is Israel's rescue. The same sovereignty that narrows the line to Isaac is why the nation survived at all. After the golden calf, only God's mercy was left.
- Promise reaches us. Those born of God, not of flesh, stand today where Isaac stood: children of promise, and so Abraham's true seed.
That is, [they that are] the children of the flesh, these [are] not the children of God; but the children of the promise are reckoned as seed.
God made His promises to Abraham's family. Yet most of Israel rejected the Messiah. Had God's word then failed? Paul answers by pointing back into Abraham's own household. Birth into that family never made anyone a child of God.
Paul is not conceding that Israel's unbelief has defeated God's promise. He is exposing the false assumption hidden inside the objection.
The word of God keeps all its force. Only man is at fault, and the Jew above all. Their objection assumed that God was bound to bless the whole race descended naturally from Abraham. But this would open the promises to the Ishmaelites. Not so, cries the Jew: the promise runs only in the line of Isaac. Then, the apostle may reply, natural descent is an unsound principle... Promise, not flesh, decides... This is universally true. Descent according to the flesh, on its own, secures no inward blessing.
If physical descent gives the title, Abraham's line and Isaac's line each bring in another nation.
You claim to be children — children of promise only, as Abraham's natural seed. But it is written, "Through Isaac shall your offspring be named." If you take it as descent according to the flesh, you must let in the Ishmaelites... And there is more. Rebecca conceived by one man, Isaac. Here no one could dodge the point by pleading a slave mother. Before the children were born, before they had done anything good or bad, it was said that the older would serve the younger. If the title goes by fleshly descent, you must let in the Edomites. If the Jew would not agree to that, he must agree to sovereignty in election.
"Children of the flesh" is not a neutral label for natural birth. It names a source that God had already judged.
The flesh can produce nothing except what is flesh. The Lord Himself declared this plainly (John 3:6), and His death set flesh aside completely and condemned it — its judicial end. Still, God knew its character from the beginning. He knew it was a corrupt source, and therefore a source of nothing but corruption. So He passed by Ishmael, the child of the flesh. His election rested on Isaac, the child of promise — the son who came into being by the resurrection power of God, as expressed in His promise of earlier years.
Isaac has the title because of how he came into the world.
One son, the elder, Ishmael, was born in the natural way... The other child, Isaac, was not. His father was a hundred years old. His mother was ninety, and had long before lost the power to have children. But God had promised that Sarah should have a son... God's promises are always true. He is the faithful God (Deuteronomy 7:9). So, in God's own time, He sent Abraham a son by Sarah his wife. This son was truly a "child of promise."
A Jewish reader would gladly use this rule to shut out Ishmael's descendants. Paul lets him agree, then turns it on him.
The Jew was ready enough to bring that statement forward as a bar to any claim the Ishmaelites might have made. He gladly agreed with it. But he did not see, until the apostle pointed it out, that it had a wider application, and one that came closer to home — dealing a death-blow to any hope of divine blessing simply on the ground of natural descent... They might, as the Lord had told them (John 8:37, 39), be Abraham's seed and yet not be Abraham's children.
Isaac is not the only child of promise in Scripture.
Samuel, like Samson, was a child of promise. A child of promise is always the sign of grace (Romans 9:8). As it says, "not of blood nor of the will of the flesh nor of the will of man, but of God."
One bishop used this verse to argue that God is finished with Israel as a nation. The reply looks two chapters ahead, to Romans 11.
The inspired apostle cannot contradict himself. The Bishop sets Romans 2 and 9 against Romans 11:25-26. But that passage, beyond any real dispute, declares that "all Israel will be saved," after the fullness of the Gentiles — now being called by the gospel — has come in... Romans 2 only insists that a bare name and outward form are worthless, and that reality counts: true now, as well as in that day. Mere fleshly descent from Israel is of no use.
- Promise decides. Natural descent never decided anything. If it did, Abraham's promises would belong to Ishmael's descendants too.
- Promise excludes flesh. Flesh can only reproduce flesh. So God passed over the child of natural strength and chose the son who existed only because God had spoken.
- Promise means power. Sarah could no longer have children. Isaac is a "child of promise" because God alone made his birth possible.
- Promise turns the argument home. The Jew used this rule against outsiders without seeing that it stripped him of any claim based on birth.
- Promise still stands. Promise, not family line, carries the blessing. So God's word has not failed, and Israel's future rests on that same grace.