In this Romans 11 chapter, Apostle Paul gives more clarification of how The Promise to Abraham by Faith involves flesh Israel...
Rom 11:1-36
1 I say then, Hath God cast away His people? God forbid. For I also am an Israelite, of the seed of Abraham, of the tribe of Benjamin.
Has God cast away His people of flesh Israel? That's what Apostle Paul is asking there. "God forbid", he says, and you might want to heed that. Paul then declares he himself is of the flesh seed of Abraham, specifically born of the tribe of Benjamin. He's saying that as proof how God has not cast away all flesh born Israelites.
2 God hath not cast away His people which He foreknew. Wot ye not what the scripture saith of Elias? how He maketh intercession to God against Israel, saying,
3 Lord, they have killed Thy prophets, and digged down Thine altars; and I am left alone, and they seek my life.
4 But what saith the answer of God unto him? I have reserved to Myself seven thousand men, who have not bowed the knee to the image of Baal.
5 Even so then at this present time also there is a remnant according to the election of grace.
Who are the people which God "foreknew"? Flesh Israel, call them "national Israel" if you want. Sorry, can't just change this to read spiritual Israel only, for what Paul says here is specifically about a 'seed' of flesh Israel. Paul then recalls how Elijah complained to God that he alone was left in following Him. But what did God say? He said He had reserved, and let's stop for a second and think about that. GOD RESERVED seven thousand of flesh Israel to Himself that had not bowed to Baal in false worship. In other words, God Himself reserved that remnant, no man did it. He did that per His promises to Israel, that they would NEVER cease to be His people, like the Book of Jeremiah also showed.
Then Paul shows, "Even so then at this present time also there is a remnant according to the election of grace." Election of Grace; does that mean they chose God first? No. It means God chose them, and that remnant is per HIS CALLING. He is NOT going to go back on His Promise to Israel, is what it's about, even though many of Israel fell away.
6 And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work.
Paul then shows God did that according to His Grace, and NOT of their own works. His preservation of a remnant of flesh Israel that believed has ALWAYS been according to His Grace, even in Old Testament times. NONE can remove the seed of Israel in that. Only God can.
7 What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded
Does Paul mean all Israel there? No, of course not, for he just testified of a remnant of Israel which God Himself reserved as a remnant according to the election of grace.
8 (According as it is written, God hath given them the spirit of slumber, eyes that they should not see, and ears that they should not hear;) unto this day.
9 And David saith, Let their table be made a snare, and a trap, and a stumblingblock, and a recompence unto them:
10 Let their eyes be darkened, that they may not see, and bow down their back alway.
That part there, is about unbelieving Israel; those of Israel which fell away. And it's especially important to note that God gave those the "spirit of slumber", closed their spiritual eyes and ears, even unto Paul's day and time. Just as God reserved a remnant of Israel to Himself, He likewise blinded the rest. And Paul is going to show why in the next verses...
11 I say then, Have they stumbled that they should fall? God forbid: but rather through their fall salvation is come unto the Gentiles, for to provoke them to jealousy.
That "spirit of slumber" God put upon the rest of Israel was so His Salvation could go to the Gentiles, and to provoke unbelieving Israel to jealousy. Now why would God want to provoke them to jealousy?
12 Now if the fall of them be the riches of the world, and the diminishing of them the riches of the Gentiles; how much more their fulness?
13 For I speak to you Gentiles, inasmuch as I am the apostle of the Gentiles, I magnify mine office:
14 If by any means I may provoke to emulation them which are my flesh, and might save some of them.
15 For if the casting away of them be the reconciling of the world, what shall the receiving of them be, but life from the dead?
Paul's talking about provoking the unbelieving of Israel so that at least some of them might turn to Christ and be saved. In the spiritual sense, the unbelieving of Israel are 'dead', and their coming to Christ would be like life from the dead. But don't get pumped up, because the unbelieving Gentiles are 'dead' also in the same sense.
16 For if the firstfruit be holy, the lump is also holy: and if the root be holy, so are the branches.
17 And if some of the branches be broken off, and thou, being a wild olive tree, wert graffed in among them, and with them partakest of the root and fatness of the olive tree;
The Root is Holy, so are the branches. The believing Gentiles represent a "wild olive tree" that is graffed in AMONG THEM, meaning among BELIEVING ISRAEL, the remnant God reserved. And the Gentile believers WITH THEM partake of the Root and fatness of the olive tree. Paul shows right there, we Gentile believers can never be separated from flesh believing Israel which God preserved according the election of grace. We both together, are to be one in Christ Jesus. There is only One Root Jesus Christ, not two Roots like one for Israel and another for Gentiles (Eph.2:11-12 comes to mind).
18 Boast not against the branches. But if thou boast, thou bearest not the root, but the root thee.
Thus Paul says, "Boast not against the branches." That means we Gentiles are not to boast against the natural branches of Israel.
19 Thou wilt say then, The branches were broken off, that I might be graffed in.
20 Well; because of unbelief they were broken off, and thou standest by faith. Be not highminded, but fear:
21 For if God spared not the natural branches, take heed lest He also spare not thee.
22 Behold therefore the goodness and severity of God: on them which fell, severity; but toward thee, goodness, if thou continue in His goodness: otherwise thou also shalt be cut off.
Paul gives specific conditions there for us Gentiles to REMAIN as branches graffed in. It is "if thou continue in His goodness". Boasting against the natural branches of Israel is not a way to continue in God's Grace of His goodness. It shows jealousy against the remnant of flesh Israel which God reserved.
23 And they also, if they abide not still in unbelief, shall be graffed in: for God is able to graff them in again.
What? If one born of flesh Israel turns to Christ and believes on His Blood shed on the cross, God is able to graff those into the Root again? YES. Does that mean into the branches of the wild olive tree, the Gentiles? NO!
24 For if thou wert cut out of the olive tree which is wild by nature, and wert graffed contrary to nature into a good olive tree: how much more shall these, which be the natural branches, be graffed into their own olive tree?
Listen up. Paul says those of flesh Israel that turn and come to Christ are "graffed into their own olive tree", since he also says they are the "natural branches". THAT means, back into God's original promises He gave to Israel, which INCLUDES the inheritances of the land, the kingdom, etc. God's Promises never ceased, and nor has Israel as a people ceased, which also is one of His promises.
25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in.
Uh, does that mean when "the fulness of the Gentiles be come in", more of flesh Israel is going to be turned to Christ? YES! That also, is one of God's promises per the Old Testament prophets. That's even where Paul is going to quote from in the next verse...
26 And so all Israel shall be saved: as it is written, There shall come out of Sion the Deliverer, and shall turn away ungodliness from Jacob:
27 For this is My covenant unto them, when I shall take away their sins.
Jer.31:31 is just one of MANY OT Scriptures where that is written. End of Jer.33 is another, Ezek.34, 37, 39:25, Isa.11; Ezek.47-48; Hosea 3; Joel 3; Amos 9; Micah 7; Zeph.3; Zech.10, and those are only a few.
28 As concerning the gospel, they are enemies for your sakes: but as touching the election, they are beloved for the fathers' sakes.
29 For the gifts and calling of God are without repentance.
How can flesh unbelieving Israel still be beloved to God? Because He chose Israel above all other nations in the beginning, He called them as His elect. Notice Paul shows clearly these are about unbelieving Israel, those whom God blinded, because these "concerning the gospel, they are enemies for your sakes", meaning for the sakes of us Gentiles, so God's Salvation could also go to us and not just flesh Israel.
30 For as ye in times past have not believed God, yet have now obtained mercy through their unbelief:
31 Even so have these also now not believed, that through your mercy they also may obtain mercy.
32 For God hath concluded them all in unbelief, that He might have mercy upon all.
Who can't understand that? In times past we Gentiles were as strangers from the covenants of Promise, outcasts from God's Plan of Salvation through His Son. Yet WE obtained 'mercy' by the unbelief of many of Israel. THAT is what their unbelief and the blindness of "spirit of slumber" God caused upon them is all... about.
And NOW, it is through OUR MERCY in Christ Jesus, that THEY also may... obtain MERCY. God did this so that His MERCY might go to ALL. So thinking all unbelieving flesh Israel is now condemned goes totally against what Paul taught here in Romans 11. It ain't over until Christ comes.
33 O the depth of the riches both of the wisdom and knowledge of God! how unsearchable are His judgments, and His ways past finding out!
34 For who hath known the mind of the Lord? or who hath been His counsellor?
35 Or who hath first given to Him, and it shall be recompensed unto Him again?
Who gave Israel to God in the first place? None did, He chose them. So who can give Israel back to Him if they have always belonged to Him?
36 For of Him, and through Him, and to Him, are all things: to Whom be glory for ever. Amen.
(KJV)