Elsewhere on my blog I’ve defended the view that, according to Hebrew prophecy, Israel is central to (and will be the main focus of) God’s redemptive plan for the earth. See, for example, the following two-part study:
We also know that, during the future time of judgment with which the book of Revelation is concerned, God will be making a distinction between the nations and the people of Israel (who will continue to exist as a people whose identity is based on their particular ethnicity/lineage and covenantal relationship with God). For example, in Revelation 7:4-8 we read the following:
And I heard the number of the sealed, a hundred and forty-four thousand sealed, out of every tribe of the sons of Israel, twelve thousand sealed out of the tribe of Judah, twelve thousand of the tribe of Reuben, twelve thousand of the tribe of Gad, twelve thousand of the tribe of Asher, twelve thousand of the tribe of Naph′tali, twelve thousand of the tribe of Manas′seh, twelve thousand of the tribe of Simeon, twelve thousand of the tribe of Levi, twelve thousand of the tribe of Is′sachar, twelve thousand of the tribe of Zeb′ulun, twelve thousand of the tribe of Joseph, twelve thousand sealed out of the tribe of Benjamin.
It’s further evident from prophecy that, following the time of divine indignation and judgment through which these forty-four thousand Israelites will be protected, God’s covenant people will have a preeminent, favored status on the earth, and will be especially blessed by God (being the primary beneficiaries of God’s favor and the recipients of divine blessing, both physical and spiritual), while the nations/gentiles will be subordinate to Israel and receive their blessings through the mediation of Israel (see the following article for a defense of this view: www.thathappyexpectation.blogspot.com/2021/08/the-status-of-israel-and-nations-on.html).
In contrast with what we find revealed in scriptural prophecy, it has been a widely-held belief among Christians throughout “church history” that the nation of Israel has already fulfilled its divine purpose and role in God’s redemptive plan (for a refutation of this view, see the following article: www.thathappyexpectation.blogspot.com/2021/09/has-gods-purpose-for-israel-already.html). According to this commonly-held understanding, the only “people of God” with whom God is presently concerned (and with whom God will be concerned during the future time period prophesied in, for example, Revelation 20:4-6) are those who belong to the primarily gentile-comprised company of saints that the apostle Paul referred to in his letters as “the body of Christ.”
For example, in a footnote for the passage from Revelation 7 quoted above, we read the following in the Revised Standard Version Catholic Edition:
: A symbolic number, i.e., twelve (the sacred number) squared and multiplied by 1,000 to denote a multitude. It is the church, the spiritual Israel, that is meant.
The “church” that’s being referred to by the Catholic author of this footnote is, of course, the Roman Catholic Church. And we know that, from the beginning of its existence, the Roman Catholic Church has been comprised primarily of gentiles (the same could be said for the Greek Orthodox Church and every major Protestant church/denomination). In other words, the view being promoted in this footnote is that those referred to as being “out of every tribe of the sons of Israel” consist primarily (if not exclusively) of people who don’t belong to any of the tribes “of the sons of Israel,” and who wouldn’t consider themselves to be under any covenant-based obligation (such as, for example, the covenant-based obligation to circumcise their children on the eighth day, or to keep the seventh-day Sabbath).
One proponent of the view that the gentile-dominated Christian church is “spiritual Israel” (and that the Jewish people are no longer central to God’s redemptive plan for the earth) has summarized this view as follows:
“The Jewish nation no longer has a place as the special people of God; that place has been taken by the Christian community which fulfills God’s purpose for Israel.”
Although the view summarized in this statement (and implied in the footnote quoted above) is contradicted by what’s actually prophesied in Scripture concerning Israel, there are a few verses from Scripture to which proponents of this position will appeal in support of it. One such passage is Romans 2:28-29.
In these verses we read the following:
“For not that which is apparent is the Jew, nor yet that which is apparent in flesh is circumcision; but that which is hidden is the Jew, and circumcision is of the heart, in spirit, not in letter, whose applause is not of men, but of God.”
According to how proponents of the view summarized above interpret these verses, the saints who comprised what Paul referred to in Romans 16:4 as “all the ecclesias of the nations” were regarded by God as being “spiritual Jews,” and as constituting a “spiritual Israel.” However, as will be demonstrated below, this is not what Paul had in mind in this passage.
When reading these verses, it’s important to understand that, at this point in his letter, Paul was not yet referring to what was true of those who had believed the evangel for which he said he’d been “severed” (Rom. 1:1). That is, Paul was not yet referring to what was true of those who had come to comprise the ecclesias referred to in Rom. 16:4 as “all the ecclesias of the nations.” Instead, from Romans 1:18 to Romans 3:20, Paul was referring to what was (and is) true for Jews and gentiles who haven’t (yet) been “justified gratuitously in [God’s] grace, through the deliverance which is in Christ Jesus” (Rom. 3:24). It’s not until Romans 3:21 that Paul shifts his focus to the new state of affairs that began when “the righteousness of God” of which we read in this verse became “manifest,” and people began to be “justified by faith apart from works” (Rom. 3:28).
In contrast with what is true of those who have been justified by faith apart from works (and for whom we’re told in Romans 5:20-21 that “grace super-exceeds…for life eonian”), the one to whom Paul referred as “the Jew” in Romans 2:28-29 is someone whose eonian destiny is based on his conduct, and whose justification is based on both faith and righteous works (for example, according to what we read in James 2:14-26, the faith by which a believer among God’s covenant people could be justified required, and had to be “perfected” by, works). In Romans 2:5-13 we read the following:
Yet, in accord with your hardness and unrepentant heart you are hoarding for yourself indignation in the day of indignation and revelation of the just judgment of God, Who will be paying each one in accord with his acts: to those, indeed, who by endurance in good acts are seeking glory and honor and incorruption, life eonian; yet to those of faction and stubborn, indeed, as to the truth, yet persuaded to injustice, indignation and fury, affliction and distress, on every human soul which is effecting evil, both of the Jew first and of the Greek, yet glory and honor and peace to every worker of good, both to the Jew first, and to the Greek. For there is no partiality with God, for whoever sinned without the law, without law also shall perish, and whoever sinned in law, through law will be judged. For not the listeners to law are just with God, but the doers of law shall be justified.
It’s evident that Paul was not referring to those in the body of Christ here, for the basis for justification and eonian life referred to in this passage is incompatible with what Paul wrote elsewhere concerning the justification and salvation of those in the body of Christ. Here, again, is the criterion by which people will be judged at the time that Paul had in view in the above passage (i.e., “in the day of indignation and revelation of the just judgment of God”):
“…Who will be paying each one in accord with his acts…”
“…who by endurance in good acts are seeking glory and honor and incorruption, life eonian…”
“…yet glory and honor and peace to every worker of good, both to the Jew first, and to the Greek.”
“…the doers of the law shall be justified.”
Contrast the above excerpts from Romans 2:5-13 with what Paul wrote in Romans 3:28 and 4:4-5:
“For we are reckoning a man to be justified by faith apart from works of law.”
“Now to the worker, the wage is not reckoned as a favor, but as a debt. Yet to him who is not working, yet is believing on Him who is justifying the irreverent, his faith is reckoned for righteousness.”
See also Eph. 2:4-9; 2 Tim. 1:8-11; Titus 3:3-7.
Since the justification and eonian destiny of those in the body of Christ is not based on our conduct (or on our being “doers of the law”), it follows that what Paul wrote in Romans 2:28-29 does not and cannot apply to those in the body of Christ. The justification that Paul had in view in Rom. 2:13 is no more based on faith apart from works (i.e., faith alone) than the justification he had in view in Rom. 3:28 and Rom. 4:4-5 is based on faith that requires works/acts in order for one to be saved.
Paul was, in the above passages, describing how, in two very different ways, two different classes of people are justified and qualify for life eonian. Paul likely intended and expected his readers to appreciate the contrast when, after getting through everything he wrote in chapter two (including his assertion that “the doers of the law shall be justified”), they finally arrived at the astounding truth introduced in chapter three (i.e., that sinners may now be “justified gratuitously in [God’s] grace, through the deliverance which is in Christ Jesus,” and that this justification is obtained “by faith apart from works of law”).
Keeping these considerations in mind, let’s now consider who, exactly, Paul had in mind when he wrote what he did in Romans 2:28-29. This can be determined by what Paul wrote in Rom. 2:17. In this verse we read that Paul began addressing someone of Jewish ethnicity who considered himself an ideal Jew. Paul goes on to point out the hypocrisy of the Jew he’s addressing, and explains how circumcision is of no benefit to those who aren’t “maintaining the just requirements of the law.”
According to Paul, the uncircumcision of any gentiles who are “maintaining the just requirements of the law” will be “reckoned for circumcision” (v. 26). That is, the righteous, law-keeping conduct of one who is uncircumcised will qualify him for the blessings that are said to be “to the Jew first” (Rom. 2:7, 10). Such righteous gentiles will, evidently, be among those who will comprise the non-Jewish “sojourners” referred to in Ezekiel 47:21-23 (and who, in the eon to come, will be “allocated an allotment in the midst of the tribes of Israel”).
Conversely, for a Jew who isn’t “maintaining the just requirements of the law,” his circumcision – which is the sign of his covenant-based relationship with God – will be of no benefit to him in the day of judgment. By his transgression of the law, he forfeits any privileges that belonged to him by virtue of being a member of God’s covenant people (it is in this sense that his circumcision “has become uncircumcision”).
After explaining what kind of Jew won’t be among those who, on the day of judgment, will be receiving the ”glory and honor and peace” that will be “to the Jew first, and to the Greek,” Paul then explains what kind of Jew will be among this group. In Romans 2:28-29 we read the following:
“For not that which is apparent is the Jew, nor yet that which is apparent in flesh is circumcision; but that which is hidden is the Jew, and circumcision is of the heart, in spirit, not in letter, whose applause is not of men, but of God.”
When Paul referred to “the Jew” in these verses, it must be kept in mind that, in the immediate context, Paul was addressing one who is ethnically Jewish (vv. 17-24), but who is not “putting law into practice,” and who “through letter and circumcision,” is a transgressor of the law (v. 25-27). That is, Paul's focus in this section of his letter is on those who are already circumcised in the flesh. In accord with this fact, the spiritual, heart-circumcision to which Paul referred is the sort of circumcision that God had long ago stated that his covenant people Israel needed in order to be pleasing to him (Deut. 10:12-16; cf. Jer. 4:4, 9:26; 31:33; Isa 51:7), and which he would do for them in the future (Deut. 30:6; cf. Ezek. 44:7-9).
What Paul wrote earlier in Rom. 2:13 should also be kept in mind when reading verses 28-29: “For not the listeners of the law are just with God, but the doers of law shall be justified.” The circumcision that is “of the heart” is that which enables the physically circumcised to be “doers of law,” and to be “maintaining the just requirements of the law.” It is these who will be justified and receive eonian life on the day when God “will be paying each one in accord with his acts.”
Now, one important point that should be kept in mind by the reader (and which I believe will help prevent misunderstanding of what Paul wrote in Rom. 2:28-29) is this: It’s impossible for Paul to have been claiming that a Jew is solely “that which is hidden,” or that the only circumcision is that which “is of the heart” (and that there is no circumcision which is “apparent in flesh”).
Even those who appeal to this verse in support of the idea that gentiles can be “spiritual Jews” would have to admit that, elsewhere in his letters, Paul used the words “Jew” and “circumcision” in accord with the original, literal meaning of these terms. For example, immediately after what Paul wrote in Romans 2:28-29, we read the following in Rom. 3:1-2:
“Then what advantage has the Jew? Or what is the value of circumcision? Much in every way. To begin with, the Jews were entrusted with the oracles of God.”
When Paul referred to “the Jew” and “the Jews” here, he was unquestionably referring to those who belong to the nation of Israel, and who are descendants of Abraham through Isaac and Jacob. Paul was not, in other words, referring to those among mankind whom he referred to elsewhere as “the nations.” In the same way, the “circumcision” of which Paul wrote here is undoubtedly that which is “apparent in flesh” (i.e., the literal sign of a Jew’s covenant relationship with God).
Another example of what Paul had in mind when he used of the term “Jew” in his letters can be found in Romans 2:9-10. In these verses we read the following:
“There will be tribulation and distress for every human being who does evil, the Jew first and also the Greek, but glory and honor and peace for everyone who does good, the Jew first and also the Greek.”
Instead of referring exclusively to one whose circumcision is “of the heart, in spirit,” the term “Jew” in these verses denotes someone who is a member of God’s twelve-tribed covenant people, Israel. Notice that Paul used the expression “the Jew” to refer to both one who “does evil” (and who will face “tribulation and distress”) and one who “does good” (and who will receive “glory and honor and peace”). Not only this, but the fact that Paul contrasted “the Jew” with “the Greek” in these verses necessarily means that Paul couldn’t have understood “the Jew” to refer to (or to include) heart-circumcised gentiles. For if “the Jew” refers to (or includes) “heart-circumcised gentiles,” then to whom does “the Greek” refer in these verses?
We thus have good reason to believe that, in Rom. 2:28-29, Paul wasn’t “broadening” the meaning of “Jew” or redefining it to mean “anyone whose circumcision is ‘of the heart,’ regardless of their ethnicity or covenantal status.” But this means that Paul must’ve been using some kind of figure of speech in these verses. To better understand what, exactly, Paul had in mind when he wrote what he did in Romans 2:28-29 (and what figure of speech he was using), let’s consider a verse in which I believe the same figure of speech is being used. In John 12:44 we read that Christ declared the following to his disciples:
“He who is believing in Me is not believing in Me but in Him who sends Me.”
Notice that Christ’s declaration appears contradictory; one cannot both be believing in Christ and not believing in him at the same time. However, when we understand Christ to have been using the figure of speech “ellipsis” (according to which certain words are left out of a statement in order to emphasize other words in the statement), the contradiction vanishes. Here is how Christ’s declaration reads with the inclusion of the words that are implied in what he was saying:
“He who is believing in Me is not believing in Me [only] but [also] in Him who sends Me.”
By omitting the words “only” and “also” from his statement (and thus making them implicit), Christ placed a greater emphasis on the words, “in him who sends me,” and thereby more forcefully communicated the truth that, when one believes in him, one is also believing in his Father (the following are some other examples in which the words “also” and/or “only” are omitted for the sake of emphasis: Matthew 6:19-20; 12:7; 10:19-20; Mark 9:37; Luke 10:20; John 6:27; Acts 5:4).
I submit that, in Romans 2:28-29, Paul was using the same figure of speech used by Christ in John 12:44 (i.e., ellipsis). The implied meaning of what Paul was communicating here can be expressed through the addition of the words “only” and “also,” as follows:
For not that which is apparent [only] is the Jew, nor yet that which is apparent in flesh [only] is circumcision; but that which is hidden [also] is the Jew, and circumcision is [also] of the heart, in spirit, not in letter, whose applause is not of men, but of God.”
By leaving out the words “only” and “also” (and thus making them implicit), Paul placed a greater emphasis on the words “that which is hidden” and “of the heart,” and thus more forcefully communicated the following truth: In order for a Jew to be pleasing to God, he must have the circumcision which is “of the heart” (and not just the circumcision that is “apparent in flesh”).
Thus, rather than broadening the meaning of “Jew” to include gentiles in Rom. 2:28-29, Paul was explaining what must be true of any Jew if he is to have “applause…of God,” and thus receive the future blessings referred to in Rom. 2:7, 10 (blessings which will be “to the Jew first, and to the Greek”). Paul did this by emphasizing the importance of having circumcision that is “of the heart, in spirit.” It is only the Jew whose heart is circumcised (in accord with what we read in Deut. 10:12-16) whose applause will be “of God,” and who will be among the Jews to whom the eonian blessings referred to in Rom. 2:7, 10 will come “first.”
In Romans 9:4-5, Paul referred to those who comprised the nation of Israel in his day as follows:
“…my brethren, my relatives according to the flesh, who are Israelites, whose is the sonship and the glory and the covenants and the legislation and the divine service and the promises; whose are the fathers, and out of whom is the Christ according to the flesh, Who is over all, God be blessed for the eons. Amen.”
The fact that Paul specified the people of Israel as being those to whom these blessings belong means that the blessings do not inherently belong to those whom Paul referred to elsewhere in his letter as “the nations.” Keeping in mind the fact that Paul had the nation of Israel in view in verses 4-5, let’s now consider what Paul went on to write in verses 6-8:
Now it is not such as that the word of God has lapsed, for not all those out of Israel, these are Israel; neither that Abraham’s seed are all children, but “In Isaac shall your seed be called.” That is, that the children of the flesh, not these are the children of God, but the children of the promise is He reckoning for the seed.
It’s a commonly-held belief among Christians that, in these verses, Paul was redefining “Israel” to include all of the believers among the nations to whom he wrote his letters (and who comprised “all the ecclesias of the nations” referred to in Romans 16:4). However, this interpretation is contrary to the fact that, throughout the remainder of Romans 9-11, Paul used the terms “Israel” and “Jew” to denote people who were Israelites/Jews with regard to ethnicity/lineage, and members of the nation of Israel (see, for example Rom. 9:24, 27, 30-31; 10:12, 19-21; 11:2, 7, 11, 14). Consider, especially, what Paul wrote in Rom. 11:25-28:
For I am not willing for you to be ignorant of this secret, brethren, lest you may be passing for prudent among yourselves, that callousness, in part, on Israel has come, until the complement of the nations may be entering. And thus all Israel shall be saved, according as it is written,
Arriving out of Zion shall be the Rescuer. He will be turning away irreverence from Jacob. And this is my covenant with them Whenever I should be eliminating their sins.
As to the evangel, indeed, they are enemies because of you, yet, as to choice, they are beloved because of the fathers.
The “Israel” on whom we’re told “callousness, in part” had come is, of course, the same “Israel” to which Paul referred earlier (e.g., in Rom. 11:7, 11), and consists of people who are Jewish with regard to their ethnicity/lineage. And in v. 28, those whom Paul referred to as ”enemies because of you” can only refer to those who were/are Israelites with regard to their ethnicity/lineage (the majority of whom were, in Paul’s day, enemies of the saints to whom Paul wrote), while the “fathers” to whom Paul was referring are the patriarchs from whom every Israelite is descended (and with whom Peter said God “covenanted” in Acts 3:25) – i.e., Abraham, Isaac and Jacob.
In light of these contextual considerations, we can reasonably conclude the following: Those who will constitute the “all Israel” who “shall be saved” will be just as ethnically Jewish as those on whom “callousness, in part” had come and those whom Paul said were ”enemies because of you” while remaining “as to choice…beloved because of the fathers.” In other words, “all Israel” refers to the majority of Israelites who will constitute the Jewish nation at the future time that Paul had in view here (and does not, therefore, refer to any who will constitute what Paul referred to as “the complement of the nations”). And since it’s reasonable to conclude that the “Israel” referred to by Paul in Rom. 9:6-8 is part of the “all Israel” that we’re told “shall be saved” in Rom. 11:25, it logically follows that those who belong to the “Israel” referred to in Rom. 9:6-8 are just as Jewish with regard to their ethnicity/lineage as those whom Paul referred to as “Israelites” in Rom. 9:4 and elsewhere.
This means that the “seed” of Abraham Paul had in view in these verses is comprised of individuals who belong to the twelve-tribed people concerning whom God said, “Circumcise to yourselves every male” (Gen. 17:10), and who are distinguished from – and indeed are defined by their distinction from – “the nations” (Gen. 26:4; 1 Chron. 16:24, 35; 17:21). For example, in Genesis 12:5-7 we read the following:
And taking is Abram Sarai, his wife, and Lot, his brother's son, and all their goods which they got, and every soul which they make their own in Charan, and forth are they faring to go toward the land of Canaan. And coming are they to the land of Canaan. And passing is Abram into the land as far as the place of Shechem, as far as the high oak. And the Canaanite is then dwelling in the land. And appearing is Yahweh to Abram and is saying to him, “To your seed am I giving this land.”
That the “seed” referred to in v. 7 is comprised of people who belong to the twelve-tribes of Israel is evident from what we’re told Yahweh later declared to Moses, as recorded in Exodus 33:1:
Go up hence, you and the people whom you brought up from the land of Egypt, to the land about which I swore to Abraham, to Isaac and to Jacob, saying: To your seed shall I give it.
And in Joshua 1:2-6 we read that, after Moses’ death, Yahweh declared the following to Joshua:
“Moses my servant is dead. Now therefore arise, go over this Jordan, you and all this people, into the land that I am giving to them, to the people of Israel. Every place that the sole of your foot will tread upon I have given to you, just as I promised to Moses. From the wilderness and this Lebanon as far as the great river, the river Euphrates, all the land of the Hittites to the Great Sea toward the going down of the sun shall be your territory. No man shall be able to stand before you all the days of your life. Just as I was with Moses, so I will be with you. I will not leave you or forsake you. Be strong and courageous, for you shall cause this people to inherit the land that I swore to their fathers to give them.“
In light of these and other related passages, there can be no question that the seed of Abraham referred to in Gen. 12:7 refers to the twelve-tribed people of Israel.
In Genesis 13:14-17 and 17:7-8 we read the following:
And Yahweh Elohim says to Abram after Lot was parted from him, “Lift your eyes, pray, and see. From the place where you now are, northward and toward the south-rim and eastward and seaward, for all the land which you are seeing, to you am I giving it, and to your seed, till the eon. And I make your seed as the soil of the land. Could a man count the soil of the land, moreover, then your seed shall be counted. Rise, walk in the land, its length and its width, for to you am I giving it, and to your seed, for the eon.”
“And I set up My covenant between Me and you, and your seed after you, for their generations, for a covenant eonian, to become your Elohim and your seed’s after you. And I give to you and to your seed after you the land of your sojournings, all the land of Canaan, for a holding eonian (or “a possession age-during”).
We also read in Exodus 32:11-13 that Moses beseeched Yahweh as follows:
“Why, Yahweh, has Your anger grown hot against Your people whom You have brought forth from the land of Egypt with great vigor and with a steadfast hand? Why should the Egyptians speak, saying: For evil He brings them forth to kill them in the mountains and to finish them off the surface of the ground? Turn back from the heat of Your anger and show mercy concerning the evil to Your people. Remember Abraham, Isaac and Israel, Your servants to whom You swore by Yourself. You spoke to them, saying: I shall increase your seed as the stars of the heavens, and all this land, as I have said, I shall give it to your seed, and they will gain it as an allotment for the eon.”
And in 1 Chronicles 16:12-18, God’s promise to give the land of Canaan to the “seed of Israel” as an allotment is referred to as a “covenant eonian”:
Remember His marvelous works that He has done, His miracles and the judgments of His mouth, O seed of Israel, His servants, sons of Jacob, His chosen ones. He is Yahweh, our Elohim; His judgments are in all the earth. Remember His covenant for the eon, the word he enjoined on a thousand generations, that He contracted with Abraham, and by His oath to Isaac. He ratified it to Jacob as a statute, to Israel as a covenant eonian, saying, “To you shall I give the land of Canaan, the region of your allotment.”
The words “till the eon,” “for the eon,” “a covenant eonian” and “a holding/possession eonian” indicate that God’s intention has always been that the offspring of Abraham, Isaac and Jacob to whom the land of Canaan has been promised will possess and enjoy this land for much longer than the relatively brief periods of time that we find referred to elsewhere (e.g., in Josh. 21:43-45 and 1 Kings 4:20-21).
Notice, also, that in the verses quoted from Genesis 13 and 17, Abraham himself is included among those to whom the land will be given “for the eon” and as “a holding eonian.” Since Abraham died long before Israel entered the land under Joshua’s leadership (and must therefore be restored to life in order to have an allotment in Canaan “for the eon”), it follows that what God promised Abraham, Isaac and Jacob concerning the land of Canaan has yet to be fulfilled.
The fact is that the very purpose for which Paul wrote Romans 9-11 was to defend the truth that, despite the unbelief of the majority of Israelites in his day, God would be faithful to his covenant-based promises concerning Israel’s redemption and prophesied destiny. Paul’s defense of this truth begins with a defense of the related truth that God’s redemptive plan for Israel has always involved his sovereign selection of some descendants of Abraham (but not others) to belong to the promised “seed” (plural) of Abraham that will enjoy the covenant-based blessings that God has in store for Israel during the coming eons. In other words, Paul’s argument is that it was never part of God’s eonian purpose that every descendant of Abraham through Isaac and Jacob belong to this promised seed.
The first step in Paul’s argument in Romans 9-11 involves an appeal to the truth that God pre-selected Isaac (rather than Ishmael) to form the lineage of the promised seed. From this fact Paul infers that mere physical descent from Abraham doesn’t include one among the promised, chosen seed (and thus among the children of God); those who constitute the promised seed are those who, like Isaac, were chosen by God in advance (and whose sonship is thus in accord with God’s “purpose according to election” – i.e., the purpose that’s manifested in the promise found in Genesis 18:10, 14, and quoted in v. 9).
Anticipating an objection that Isaac and Ishmael had different mothers, Paul then appeals to the case of Jacob and Esau (who, being twins, had the same father and mother). Before they were born, God chose (and made known his choice of) Jacob rather than Esau to belong to the promised seed. Paul’s appeal to God’s choice of Isaac and Jacob establish the principle that God’s selection of some and exclusion of others has never been based on anything that distinguishes one individual from another (including anything that an individual has or hasn’t done). Instead, the ultimate reason and explanation for why any Israelite belongs to the promised, chosen seed (and will thus be the beneficiaries of God’s covenant-based blessings concerning this seed) is God himself.
Moreover, it’s evident that the words “children of the flesh” in Rom. 9:8 cannot refer to everyone who is an Israelite with regard to ethnicity/lineage (for if that were the case, Paul would’ve been excluding all ethnic Israelites from being “children of the promise”). The “children of the flesh” to whom Paul was referring can only refer to those among God’s covenant people who, by virtue of having been “hardened” by God (Rom. 9:18; 11:7), remained in unbelief. But since that’s the case – and since Paul consistently used the terms “Israel” and “Jew” throughout the remainder of Romans 9-11 to denote ethnic Israelites/members of God’s covenant people – we can reasonably conclude that the “children of the promise” whom God is “reckoning for the seed” are also Jewish with regard to their ethnicity. That is, in Rom. 9:6-8, Paul was simply distinguishing between two kinds of Israelites/Jews when he referred to “the children of the flesh” and the “children of the promise.”
Those whom Paul said were being “reckoned for seed” (or “counted as descendants”) were Israelites who, like Isaac and Jacob, had been chosen by God (Rom. 9:9-13), and – in accord with God’s purpose and intention – were “vessels of mercy” rather than “vessels of indignation” (Rom. 9:19-23). Having been chosen by God, they had come to believe the truth that Jesus “is the Christ, the Son of God” (which is the foundational truth that constitutes the “evangel of the Circumcision” referred to by Paul in Gal. 2:7).
These believing Israelites are later referred to by Paul as the “remnant chosen by grace” and “the chosen” in Rom. 11:5-7:
“At the present time there is a remnant chosen by grace. And if it is by grace, it is no longer by works, otherwise grace would no longer be grace. What then? Israel failed to obtain what it was diligently seeking, but the elect obtained it. The rest were hardened…”
This Jewish remnant is necessarily constituted by the believers among God’s covenant people (i.e., those Israelites on whom callousness had not come), and thus comprised the part of the “entire seed” referred to in Rom. 4:16 who were “of the law.” In contrast, the Israelites referred to in the above verses as “Israel” and “the rest” are identical with those previously referred to in Rom. 9:8 as “the children of the flesh.” They are referred to as “children of the flesh” not because they’re ethnic descendants of Abraham, Isaac and Jacob, and belong to the nation of Israel (for, again, the remnant/children of the promise are also Israelites with regard to their ethnicity); rather, the “children of the flesh” are referred to as such because of what they lack (which is faith in their Messiah, Jesus). Being without faith, their identity – relatively speaking – is based solely on their flesh (which is, of course, insufficient to make them “children of the promise”).
Rather than broadening the meaning of “Israel” in Rom. 9:6 to include believers among the nations (i.e., members of the body of Christ), Paul was narrowing the meaning to exclude calloused, unbelieving Israelites. The “Israel” to which God is going to be giving the eonian allotment promised in (for example) Genesis 17:7-10 is going to include believers among the nation only. This group is a subcategory of those who are referred to as “Israelites” in Romans 9:4, and in Paul’s day consisted only of those who had been called by God through the heralding of “the evangel of the Circumcision,” and who had thus come to believe the truth of Jesus’ Messianic identity (concerning which the majority of Israelites continued in unbelief). It is these Israelites who will be the enjoyers of the eonian allotment that God promised to both Abraham and his seed (i.e., the “seed” that refers to a plurality of offspring), in fulfillment of verses such as Genesis 12:7, 13:15, 15:18, 17:8, 24:7, Josh. 1:4, etc.
 Bruce Waltke, “Kingdom Promises as Spiritual,” in Continuity and Discontinuity: Perspectives on the Relationship Between the Testaments, Ed. John S. Feinberg [Wheaton, Illinois: Crossway, 1987] p. 275).