1. Introduction

Paul’s heart aches for his kinsmen. At the start of Romans 9, he pours out sorrow that so many in Israel—God’s own covenant people—have rejected their Messiah (Rom. 9:1–3). How could it be that those who were given unparalleled privileges have failed to embrace the promised Christ? After all, Israel was blessed with “the adoption, the glory, the covenants, the giving of the law, the worship, and the promises”, not to mention the patriarchs—and even the Messiah came “from their race, according to the flesh” (Rom. 9:4–5). With so much given, one might ask: Has God’s word to Israel failed? Did the Lord’s promise fall short because many ethnic Israelites remain in unbelief? Paul’s resounding answer is No. God’s covenant word has not fallen to the ground. But to understand why, we must grasp a crucial distinction Paul makes—a distinction between physical descent and divine election.

In Romans 9:6 Paul unveils the principle that unlocks the puzzle: “But it is not as though the word of God has failed. For not all who are descended from Israel belong to Israel.” In a shockingly paradoxical phrase, he asserts that being born an Israelite does not automatically make one part of the true Israel of God. There is an Israel within Israel, an elect remnant chosen by grace (as Paul will later say in Rom. 11:5–7). God’s saving promises were never guaranteed to every physical descendant of Abraham. They were always realized in the children of promise—those whom God calls and elects by His mercy (Rom. 9:7–8). Paul had hinted at this earlier in the letter when he wrote that a true Jew is one inwardly, whose heart is circumcised by the Spirit, not merely one outwardly (Rom. 2:28–29). Now, in chapter 9, he demonstrates this truth from Israel’s own history.

Strikingly, as Paul builds his case that “not all are children of Abraham because they are his offspring” (Rom. 9:7), he sticks to examples drawn strictly from within Abraham’s physical lineage. He says nothing here about Gentile converts (proselytes) or outsiders joining Israel’s blessings. Instead, he reaches back to the patriarchs to show that God’s promise operates on His sovereign choice, not on natural descent or human effort. By examining Paul’s illustrations—Isaac vs. Ishmael, and Jacob vs. Esau—we will see how election, not ethnicity or family line, has always been the determining factor in who inherits God’s promise. In doing so, we will also consider why Paul pointedly remains silent about proselytes in this passage, and how that silence itself is instructive for his theological purpose.

2. “Not All Who Are Descended from Israel Belong to Israel” (Romans 9:6)

Paul’s thesis comes early and emphatically: God’s word has not failed. The apparent unbelief of much of Israel does not mean God’s plan went wrong. Why? “For not all who are descended from Israel belong to Israel” (9:6). In other words, there has always been a distinction between ethnic Israel (the nation as a whole) and spiritual Israel (the subset of true believers and heirs of the promise). The name “Israel” itself hints at this double meaning—Jacob was renamed Israel by God, yet within Jacob’s own descendants there would be those who truly carried his legacy of faith and those who did not.

Paul is essentially saying: God’s promises were never given to ethnic Israel in the blanket way you assume. From the beginning, God made choices within Abraham’s family. The history of Israel is a history of God’s electing grace, narrowing down the line of promise according to His own will. Therefore, the unbelief of many Israelites doesn’t nullify God’s promise, because that promise was never based on mere physical descent. As theologian John Murray explains, God’s covenant promise “did not have respect to Israel after the flesh [ethnic Israel] but to [the] true Israel,” so the unbelief of natural Israel “in no way interfered with the fulfillment of God’s covenant purpose and promise.”covreformedchurch.org In short, God’s word stands—because God is fulfilling it in the faithful remnant and the heirs of promise, just as He always intended.

To drive this point home, Paul reminds his readers of two critical episodes from Genesis. These examples prove that being Abraham’s child according to the flesh was never sufficient to guarantee a share in God’s redemptive plan. Divine election cut right through natural family lines, such that even among Abraham’s own sons and grandsons, God’s saving promise came only to those He chose. Let’s look at each case.

3. Election over Descent Illustrated: Isaac, Not Ishmael (Romans 9:7–9)

Paul’s first example contrasts Abraham’s two sons: Ishmael and Isaac. Both boys had Abraham as their father, yet only one was counted as Abraham’s true heir in God’s covenant plan. “Not all are children of Abraham because they are his offspring,” Paul writes, “but ‘Through Isaac shall your offspring be named’” (Rom. 9:7). Here Paul quotes Genesis 21:12, where God insisted to Abraham that the covenant line would continue through Isaac, the son born to Sarah, not through Ishmael, the son of Hagar. At God’s command, Abraham had to send Ishmael away, even though Ishmael was his natural son, because God had chosen Isaac alone as the child of promise (Gen. 21:12–13).

What is the lesson Paul draws? “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” (Rom. 9:8). Ishmael was a “child of the flesh” in the sense that he was born by the ordinary course of nature and human planning. Isaac, on the other hand, was the “child of promise” – conceived by God’s miraculous intervention in fulfillment of His word to Abraham and Sarah. Isaac’s birth happened because God promised it (Gen. 18:10, 14), showing that the true seed of Abraham are those brought about by God’s promise and purpose, not merely by bloodline. No human scheming or natural procreation could produce the heir of the covenant; only God’s sovereign promise could.

By highlighting Isaac over Ishmael, Paul reminds his readers that from the very start of Israel’s story, God made a distinction among Abraham’s children. The chosen line ran through a specific son according to God’s gracious decision. Ishmael was certainly blessed in a general way (God did make him a great nation as well), but the covenant blessings—the saving relationship leading to the Messiah—flowed exclusively through Isaac. In the eyes of Paul’s argument, this proves that physical descent from Abraham is not enough to be counted as a child of God’s promise. If it were, Ishmael would have been just as much a child of promise as Isaac, yet he was not. The deciding factor was God’s call and promise, not who Ishmael’s father was.

It’s important to note that at this point Paul still hasn’t introduced any Gentiles into the equation. He’s talking about two physical sons of Abraham. A Jewish reader could not object that Paul was comparing apples to oranges—these are both members of Abraham’s household! Yet God chose one and not the other. The silence about any proselytes or Gentile believers here is deliberate: Paul is keeping the focus on Israel’s own patriarchal lineage to make an undeniable case. If Abraham’s own flesh-and-blood child could be excluded from the covenant line, then surely membership in God’s people was never simply a matter of flesh. It depended on God’s promise. In other words, Isaac’s election and Ishmael’s exclusion were entirely in God’s hands—a pattern that anticipates how God works out His purpose in every generation.

Before anyone thinks that Isaac was chosen because he was in some way better or more deserving than Ishmael, Paul moves to a second, even more dramatic example. This time the contrast will eliminate any notion of human merit, effort, or advantage as the basis for God’s choice.

4. Grace before Birth: Jacob, Not Esau (Romans 9:10–13)

If the Isaac/Ishmael story illustrates that lineage alone doesn’t secure God’s promise, the story of Jacob and Esau goes a step further. It shows that God’s election is unconditional—based solely on His own free decision, made before any human could do anything to merit it. Paul writes: “And not only so, but also when Rebekah had conceived children by one man, our forefather Isaac, though they were not yet born and had done nothing either good or bad—in order that God’s purpose of election might continue, not because of works but because of him who calls—she was told, ‘The older will serve the younger.’ As it is written, ‘Jacob I loved, but Esau I hated.’” (Rom. 9:10–13).

Consider the setup: Same parents, same pregnancy, twin brothers. Unlike Isaac and Ishmael, who had different mothers and very different circumstances, Jacob and Esau shared everything humanly possible up to the moment of birth. Yet before they were born, before they had taken a breath or committed a single act, God made a distinction between them. He declared that the older (Esau) would serve the younger (Jacob), a reversal of normal expectation (Gen. 25:23). And later Scripture (in Malachi 1:2–3) poignantly summarizes God’s differing stance toward the two: “Jacob I loved, but Esau I hated.” Paul cites that blunt phrase to drive home the shocking truth of divine election: God loved (chose, set favor upon) Jacob, and hated (rejected, did not choose) Esau. His choice of Jacob was not a response to anything in Jacob (for God announced it before the boys did anything good or bad); it was a decision springing entirely from “Him who calls.” It was God’s free purpose of election at work, ensuring that His plan would stand not on human works or birth order, but on His own calling and mercy.

By choosing the younger over the elder in advance, the Lord made it clear that His favor isn’t bound by our customs or claims. In ancient culture, the firstborn would normally have the birthright and preeminence. But God is not bound by human rules of primogeniture. He overturned the natural order to make a theological point: entrance into His covenant and the achievement of His redemptive plan depend solely on His grace, not on any privilege of birth or performance. Jacob became the heir of promise purely because God willed to call him so, not because Jacob earned it (indeed, Jacob’s later life would show many flaws, but God’s choice of him never wavered). Likewise, Esau, though the firstborn and strong, did not receive the covenant blessings. This was decided before Esau ever had the chance to do either right or wrong, so that no one could say God’s choice was a reaction to human deeds. The twin story underscores that God’s election is entirely unmerited and arises from His own sovereign freedom.

At this juncture, we should address an important point: some interpreters argue that the Jacob/Esau example is only about nations or roles, not about individual salvation. After all, the Malachi quote (“Jacob I loved, Esau I hated”) originally refers to the nations of Israel and Edom, and indeed Jacob became the father of the Israelites and Esau of the Edomites. It’s true that there are corporate implications—Paul is certainly aware that Jacob’s descendants are God’s covenant people. However, Paul’s emphasis here is on God’s principle of choosing apart from works or lineage, and he applies it to the persons Jacob and Esau as representatives. The very wording “though they were not yet born and had done nothing good or bad” focuses on these two individuals in utero, not on their nations’ works. And the purpose clause “in order that God’s purpose of election might continue (or stand)” shows that God’s action with Jacob and Esau exemplifies how His electing purpose operates generally. It operates by grace, not by works, by calling, not by human willing. Paul will soon draw out the implication that this is how God shows mercy to whomever He wills, and hardens whomever He wills (Rom. 9:15–18). In fact, the very next verse after this example (Rom. 9:14) raises the question, “What shall we say then? Is there injustice on God’s part?” That anticipated objection only makes sense if Paul’s readers understood him to be saying God unconditionally chooses some and not others. If Paul were merely talking about nations in a purely historical or non-salvific sense, no one would likely accuse God of injustice for preferring Israel over Edom—as that was a familiar theme. The shock is that Paul applies these texts to God’s sovereign choice in a way that challenges human notions of fairness. He expects the reader to gasp, “Wait, if God loved Jacob and not Esau before they did anything, how is that fair?” Paul then defends God’s righteousness in election (9:14–18) and the Creator’s right over the clay (9:19–21), confirming that the point was indeed about individual mercy and hardening, not merely corporate identity.

So then, in Jacob and Esau we have a powerful demonstration of election not based on works or ethnic privilege. God’s promise continued through Jacob’s line by God’s free choice alone. This serves Paul’s larger argument perfectly: it proves that God’s word of promise had not failed—it was being fulfilled exactly as God always intended, in the Israel of promise (like Jacob), not in those who were Israel only by flesh (like Esau, who, though a son of Isaac, did not carry on the covenant). Crucially, Paul did not bring up any Gentiles or proselytes here either. Jacob and Esau are both Jewish patriarchs (twin grandsons of Abraham). The scope of examples remains squarely inside the family of Israel. And this fact sets the stage for Paul’s next move, where he will indeed extend the principle to both Jews and Gentiles in the people of God (see Rom. 9:24–26). But first, by staying within Israel’s lineage, Paul has made an unassailable case to any Jewish objector: God’s promise hasn’t failed, because God never promised that every descendant of Abraham or Isaac would be chosen. On the contrary, He has always exercised His right to choose whom the promise will flow through. Unbelief in part of Israel is not a failure of God’s plan but a feature of it, as hard as that may be to accept.

5. The Silence on Proselytes: Why Paul’s Argument Stays “In-House”

Having examined these examples, we can now appreciate why Paul conspicuously omits any mention of proselytes (Gentile converts to Judaism) in Romans 9:6–13. In a discussion about who truly belongs to Israel and who inherits the promise, one might expect Paul to address the status of Gentiles who came to faith. After all, the inclusion of believing Gentiles and exclusion of unbelieving Jews was a live question in the early Church. Yet Paul says nothing about that here. Why? Because bringing Gentiles into the argument at this stage could cloud the issue he’s tackling. The immediate problem on the table is explaining Jewish unbelief in light of God’s promises. Paul handles this by first demonstrating God’s elective principle within Israel’s own story. Only later will he explicitly apply the principle to the inclusion of Gentiles (see Rom. 9:24, where he asserts God’s calling of people from among Gentiles, and the citations of Hosea about Gentiles becoming “my people” in 9:25–26).

By staying “in-house” with his illustrations (Abraham’s household, then Isaac’s household), Paul is effectively cutting off a common escape route. A Jewish interlocutor might be tempted to blame Israel’s unbelief on the Gentiles or some outside factor—“Perhaps God’s promise failed because Gentiles are now taking part in it,” or “Maybe those not saved are just those who became like Gentiles.” But Paul doesn’t allow that line of thinking. He shows that even when only Israelites are in view, God has always differentiated among them. The promise was never about simply being born into the right family or adopting the outward signs of that family’s religion; it was about God’s promise and call. By not mentioning proselytes, Paul keeps the focus on the core issue: many ethnic Israelites are not saved because they were never children of promise to begin with, much like Ishmael and Esau were not heirs of the covenant blessing, though they were kin.

Moreover, Paul’s silence on proselytes is tactical: had he introduced Gentile converts into the argument too soon, his Jewish readers might have become defensive or tuned out. The issue of Gentile inclusion was contentious (as seen in Acts and Paul’s other letters). But by first establishing from Israel’s own Scriptures that God’s electing freedom has always operated within Israel, Paul prepares his readers to accept that this same freedom could extend salvation to Gentiles and leave some Jews hardened, all without compromising God’s righteousness or faithfulness. In essence, Paul secures the principle—God’s covenant blessings are dispensed by mercy, not by race or effort—on ground that his Jewish audience already accepts: the stories of the patriarchs. Only then does he widen the lens to show how that principle is working out in the current Jew-Gentile makeup of the Church.

It’s also noteworthy that no Jewish proselyte (Gentile-to-Jew convert) is cited as an example of a “child of promise” here. Paul could have, for instance, invoked someone like Ruth (a Moabite who joined Israel and became an ancestor of Christ) to show that Gentiles with faith can be counted as true children of Abraham. He doesn’t do that in Romans 9. That doesn’t mean Paul was unaware that Gentiles could inherit the promise (he spends much of Romans and Galatians arguing that very thing!). Rather, it shows how laser-focused he is at this juncture. The absence of proselytes in his argument is itself a message: the problem of Israel’s unbelief can be explained without reference to the Gentiles at all. It’s not that Gentiles muscled in and took Israel’s blessing; it’s that within ethnic Israel, God’s promise was never given to all equally. There were believing children of promise and others who were only children of the flesh. This was true in Abraham’s day, in Isaac’s day, and in Paul’s day as well. The tragically large number of Jews rejecting Christ are, like Ishmael or Esau, not part of the line through which the promise continues—while a remnant of Jews (like Isaac and Jacob) believe and are saved, joined by multitudes of Gentiles who are grafted in by faith (Paul will expand on that in Romans 11).

But here we must pause and observe something striking: Paul does not appeal to the many Old Testament examples of Gentiles being welcomed into Israel through allegiance to Yahweh. He could have. The story of Ruth the Moabite, for instance, would have offered a compelling illustration of someone outside the covenant people who, through faith and loyalty to Israel’s God, was grafted into the covenant line and even became an ancestor of the Messiah. Similar examples could have been drawn from Rahab, Naaman, or the “mixed multitude” that left Egypt. Each of these stories highlights that God’s mercy is not restricted to ethnic Israel and that Gentiles have long been included through confession and covenant allegiance.

Yet Paul intentionally bypasses this entire line of argument. Why? Because it would open the door to interpret inclusion as dependent on human action—on choosing, converting, aligning with the right God. Such a move, however true in one sense, would undercut the precise point Paul is making: election precedes all human activity. God’s choice of Isaac over Ishmael and Jacob over Esau was not based on lineage, faith, allegiance, or works—it was based solely on His sovereign will and purpose of election. Had Paul appealed to Ruth, his opponents could have easily argued she was “secretly” of Abrahamic lineage or that her inclusion was earned by her decision to cling to Naomi’s people and God. But Paul’s argument is designed to eliminate all such ambiguity. By choosing examples from within Abraham’s household—where genealogy is uncontested and merit is ruled out—Paul leaves no room for the objection that inclusion in God’s people is based on effort, ethnicity, or covenant allegiance. It is based on God’s call alone.

In summary, Paul’s silence on proselytes in Romans 9:6–13 serves to strengthen his case to a Jewish audience. It avoids unnecessary controversy early on and roots his defense of God’s faithfulness in familiar ground. Only Israelites are in view in these examples, so the only variable at play is God’s electing purpose. And that purpose, Paul shows, has always operated independently of ethnic boundaries or human striving. Once that is established, the door is open to understand how Gentiles can be included in the family of Abraham (by the same principle of gracious election) without implying that God’s word failed to the sons of Abraham. In fact, God is calling Gentiles into His people in accord with His promise, right alongside the believing Jewish remnant, as the next verses of Romans 9 affirm.

6. Conclusion: God’s Promise Stands on the Foundation of Election

Romans 9 confronts us with a God who is utterly sovereign in how He fulfills His promises. Far from failing, God’s word to Israel is being fulfilled in a deeper, more selective way than many expected. Not all Abraham’s descendants were chosen—and God never said they would be. Instead, “through Isaac shall your offspring be named”: God’s saving covenant followed the line of promise, not the line of mere blood. And among Isaac’s sons, it was Jacob, not Esau, who carried forward God’s purpose “in order that God’s purpose of election might stand”. What seemed to some like a breakdown of God’s plan (with so many Jews not believing in Jesus) was actually consistent with the pattern God had shown from the beginning: He has mercy on whom He wills. His promise never guaranteed salvation to every Israelite by birth, but it absolutely guarantees salvation to every individual He has elected—every true child of promise.

By temporarily leaving Gentiles and converts out of the picture in Romans 9:6–13, Paul establishes this crucial truth on uncontested ground. Then, having established it, he brings the Gentiles into the picture (Rom. 9:24–26) as additional proof of God’s freedom to save whom He wills. The end result is a theologically rich understanding: God is faithful to His word, but His word declared His freedom in showing mercy all along. He chose Isaac freely, chose Jacob freely, and now, through the gospel, He is freely choosing children of Abraham from every tribe and tongue — yet always by the same principle of gracious election, never based on human lineage or effort.

For us today, the message remains clear and profound. Being born into a Christian family, growing up in church, or performing religious works does not make anyone a true child of God’s promise. What matters is God’s call and our response of faith wrought by His mercy. “It depends not on human will or exertion, but on God, who has mercy,” as Paul will say a few verses later (Rom. 9:16). This truth is humbling. It silences pride of pedigree and self-reliance. It reminds us that salvation is always owed to God’s grace from start to finish. If we believe in Christ, we are like Isaac—children born of promise, a miracle of God’s mercy—when we could just as easily have been left in unbelief like Ishmael. We are like Jacob—grasped by God’s love despite our unworthiness—when we could have been passed over like Esau.

Paul’s teaching in Romans 9 leads us ultimately to marvel at the justice and mercy of God. His justice is vindicated, for He has kept His word—His promises never entailed what we assumed. And His mercy is illuminated, shining as the only reason anyone is saved at all. Later in Romans, as Paul concludes this whole discussion of Israel and the Gentiles, he bursts into praise: “Oh, the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgments and how inscrutable his ways!” (Rom. 11:33). Indeed, God’s ways in election transcend our understanding, but they are perfectly consistent with His faithful character. He elects, He calls, and His word stands. Romans 9 assures us that no amount of human rebellion can thwart God’s redemptive plan. The true children of Abraham—those foreknown and called by God, from Jews and Gentiles alike—will receive the promised salvation. And this has been God’s way from the beginning: election, not descent; grace, not race; promise, not proselyte status. In that sovereign grace, both humility and hope find their anchor, and God’s promises find their “Yes and Amen” in Christ.