Romans 15:26-27 (NKJV)
26 For it pleased those from Macedonia and Achaia to make a certain contribution for the poor among the saints who are in Jerusalem.
27 It pleased them indeed, and they are their debtors. For if the Gentiles have been partakers of their spiritual things, their duty is also to minister to them in material things.
Behold, the days come, saith the LORD, that I will make a new covenant with the house of Israel, and with the house of Judah: Not according to the covenant that I made with their fathers in the day that I took them by the hand to bring them out of the land of Egypt; which my covenant they brake, although I was an husband unto them, saith the LORD:
The Gentiles are partakers of the NEW Covenant, not the Old one.
Romans 11:16-26 (NKJV)
16 For if the firstfruit is holy, the lump is also holy; and if the root is holy, so are the branches.
17 And if some of the branches were broken off, and you, being a wild olive tree, were grafted in among them, and with them became a partaker of the root and fatness of the olive tree,
18 do not boast against the branches. But if you do boast, remember that you do not support the root, but the root supports you.
19 You will say then, “Branches were broken off that I might be grafted in.”
20 Well said. Because of unbelief they were broken off, and you stand by faith. Do not be haughty, but fear.
21 For if God did not spare the natural branches, He may not spare you either.
22 Therefore consider the goodness and severity of God: on those who fell, severity; but toward you, goodness, if you continue in His goodness. Otherwise you also will be cut off.
23 And they also, if they do not continue in unbelief, will be grafted in, for God is able to graft them in again.
24 For if you were cut out of the olive tree which is wild by nature, and were grafted contrary to nature into a cultivated olive tree, how much more will these, who are natural branches, be grafted into their own olive tree?
25 For I do not desire, brethren, that you should be ignorant of this mystery, lest you should be wise in your own opinion, that blindness in part has happened to Israel until the fullness of the Gentiles has come in.
26 And so all Israel will be saved, as it is written: “The Deliverer will come out of Zion, And He will turn away ungodliness from Jacob;
Notice this from vs. 17: were grafted in among them, and with them became a partaker of the root
Notice vs. 24: how much more will these, who are natural branches, be grafted into their own olive tree?
The Olive Tree is not "Israel".
I found a resource that explains this perfectly:
It is quite evident from the scriptures, as well as nature itself, that the root of a tree is its support system, and not vice versa (verse 18). So that the branches grafted in cannot boast against the branches broken off, as the root is the reason that they thrive there. So there is no reason for pride of the Gentiles in any idea that as Christians come into the Covenbant and stand by their own merit. For the Root represents Christ (Isaiah 53:2; Romans 15:8-12; Colossians 2:6-7; Revelation 5:5), the source of God's fulfillment of the Covenant in the Promised blessings to Israel. It is the Root (Christ) through whom the tree receives the sustenance of life. In this portrait, we have to understand that without the Messiah as the Root through whom comes the fatness, all believers (both Jew and Gentile) would be disassociated from Israel and the Covenant. That's how the Olive tree represents God's Covenanted people. Not is them, but represents them. Just as the Holy Temple represents God's people, this tree is a token of God's anointed people. And from comparing scripture with scripture, we learn from God's cryptic illustrations of the Olive Tree that:
#1. The Olive Tree symbolizes one Covenanted congregation of God, not two.
#2. From branches being Grafted in the Olive Tree, it cannot be the nation of Israel.
#3. The Olive Tree cannot possibly be spiritual, unreproveable, Israel.
#4. Contrary to Greek mythology, the Olive Tree does not symbolize peace or fertility.
So What does the Olive Tree symbolize? Look again at verse seventeen: "And if some of the branches be broken off, and thou, being a wild Olive Tree, wert grafted in among them, and with them partakest of the root and fatness of the Olive Tree..." Clearly the wild Olive Tree symbolizes the children of the nations of the world who were not God's Covenanted people, coming in to the Covenant relationship "with the Jews." Even as it was prophesied or written before, which is exactly what verses 26 and 27 declare. God uses this Olive tree to illustrate that the Promise of a Deliverer to Israel is fulfilled, and point blank says, for this is My Covenant with them:
"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:
For this is my covenant unto them, when I shall take away their sins."
It was long ago prophesied that the Messiah would come and take away the sins of Israel, and God is declaring that's what this Covenant Tree symbolizes. These are God's Covenanted people, Jew and Gentile alike, fulfilling that prophesy. So the Olive Tree can neither represent the political nation of Israel, nor the New Testament Church. It signifies the Covenanted people of the congregation of Israel, made up of both Jew and Gentile.
"For he is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh:
But he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God."
Not as though the word of God has been made of no effect by this, because in God's eyes they are not all Israel, which are of Israel. No Israel is Israel by flesh or heredity, but the children of the promise are counted for the seed. Jew or Gentile, they are all the Israel of God through the Promised Deliverer. So despite the irrational denials and much rhetoric about this idea being "Replacement Theology," it is clear that Gentiles are grafted in among them, and enjoy the fatness with them, through the sustenance of the Root. The Gentiles don't replace Covenant Israel, they join with the Jews within Covenant Israel. Unambiguously, God does not separate the Jews and the Gentiles into two distinct or separate Covenanted congregations. The Gentiles come into this very same Covenanted relationship with God "among" the Jews. In part, some branches are cut off from the Covenant in their unbelief and are separated from the Olive Tree or Covenant. And thus they are no more in a Covenant Israel relationship with God than anyone else in the world. And Romans chapter eleven continues with this theme of God's complete sovereignty in deciding who He will have as the Covenanted Israel of God. In other words, the remnant people for whom the Promises actually pertained.
Romans 9:1-13 (NKJV)
1 I tell the truth in Christ, I am not lying, my conscience also bearing me witness in the Holy Spirit,
2 that I have great sorrow and continual grief in my heart.
3 For I could wish that I myself were accursed from Christ for my brethren, my countrymen according to the flesh,
4 who are Israelites, to whom pertain the adoption, the glory, the covenants, the giving of the law, the service of God, and the promises;
5 of whom are the fathers and from whom, according to the flesh, Christ came, who is over all, the eternally blessed God. Amen.
6 But it is not that the word of God has taken no effect. For they are not all Israel who are of Israel,
7 nor are they all children because they are the seed of Abraham; but, “In Isaac your seed shall be called.”
8 That is, those who are the children of the flesh, these are not the children of God; but the children of the promise are counted as the seed.
9 For this is the word of promise: “At this time I will come and Sarah shall have a son.”
10 And not only this, but when Rebecca also had conceived by one man, even by our father Isaac
11 (for the children not yet being born, nor having done any good or evil, that the purpose of God according to election might stand, not of works but of Him who calls),
12 it was said to her, “The older shall serve the younger.”
13 As it is written, “Jacob I have loved, but Esau I have hated.”
Who is not Israel? The Jews who rejected Messiah Yeshua (Jesus).
Romans 2:28-29 (NKJV)
28 For he is not a Jew who is one outwardly, nor is circumcision that which is outward in the flesh;
29 but he is a Jew who is one inwardly; and circumcision is that of the heart**, in the Spirit, not in the letter; whose praise is not from men but from God.
** Deuteronomy 10:16 As far back as then... so Romans 9:6 divides Israel in two (spirit / physical) picked up in Romans 11:16-26 natural branches that remain and natural branches cut off) calling those in the Olive Tree (grafted in as well) "All Israel" does it not?
There is a division between the nation of the Jews and the remnant of the Jews who entered into the new covenant.
This has nothing to do with the Gentiles.
Galatians 6:13-16 (NKJV)
13 For not even those who are circumcised keep the law, but they desire to have you circumcised that they may boast in your flesh.
14 But God forbid that I should boast except in the cross of our Lord Jesus Christ, by whom the world has been crucified to me, and I to the world.
15 For in Christ Jesus neither circumcision nor uncircumcision avails anything, but a new creation.
16 And as many as walk according to this rule, peace and mercy be upon them, and upon the Israel of God.
Is the "Israel of God" just the believing Jews? If so, then why in the same book...
Galatians 3:24-28 (NKJV)
24 Therefore the law was our tutor to bring us to Christ, that we might be justified by faith.
25 But after faith has come, we are no longer under a tutor.
26 For you are all sons of God through faith in Christ Jesus.
27 For as many of you as were baptized into Christ have put on Christ.
28 There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus.
From the above source:
In Romans chapter eleven God is referencing Old Testament scriptures concerning a Covenantal analogy that would be known by those comparing scripture with scripture. The wording "so shall ye be my people, and I will be your God" points to Christ the Deliverer out of Zion prophesied to save Israel. This is the analogy of the Covenant Tree of Israel. And from this illustration in Romans we see that there is not a new Israel, nor a separated Israel, as it is the exact same Covenanted congregation. It merely has more of an inclusion of the Gentiles. And we must be clear on what this imagery represents before we can have any chance of truly understanding what is being said here about the Olive Tree as the one people of God, and the true Israel of God. For there is the distinction seen here between the natural Olive Tree branches, which are the Jewish people, who are originally Covenant Israel. And the wild Olive Tree branches, which are the people of the Gentile nations who now become Covenanted children of God also. That those which were not originally His Covenanted people, are now brought into God's Covenant relationship with Israel. Once separated as foreigners from Israel, they now become children of God and heirs of that same Covenant with Israel.
"For ye are all the children of God by faith in Christ Jesus.
For as many of you as have been baptized into Christ have put on Christ.
There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
And if ye be Christ's, then are ye Abraham's seed, and heirs according to the Promise."
Jew and Gentile are now one family, made one body, become branches of this one Covenant Israel that is represented by the Olive Tree. And God anticipates the obvious objection (Romans 11:1 that some will erroneously think that this would mean that the Promise to Israel of a New Covenant and an everlasting inheritance has been abrogated. God forbid! But the Promise, the Covenant and the Israel of God, shall be defined by God, not by the misguided, misinformed or mistaken. If we are in Christ, the only way anyone can be the true Israel (Hosea 11:1; Hosea 14:5-6; Matthew 2:15; Galatians 3:16-17), then we are all Abraham's seed and inheritors or heirs according to the promises (John 8:33; Galatians 3:28-29) to Israel.
Philippians 3:1-3 (NKJV)
1 Finally, my brethren, rejoice in the Lord. For me to write the same things to you is not tedious, but for you it is safe.
2 Beware of dogs, beware of evil workers, beware of the mutilation!
3 For we are the circumcision, who worship God in the Spirit, rejoice in Christ Jesus, and have no confidence in the flesh,
Paul, as a remnant Jew in the New Covenant is speaking to those of the Gentile remnant, maybe remnant Jews as well, about the New Covenant in Messiah.
To claim that "the Church" replaces Israel denies that there is a new covenant, or that being a Jew means nothing. But Paul rejects that claim.
1 Then what advantage has the Jew ? Or what is the benefit of circumcision ? 2 Great in every respect. First of all, that they were entrusted with the oracles of God. 3 What then ? If some did not believe, their unbelief will not nullify the faithfulness of God, will it? 4 May it never be! (Romans 3)
John 4:21-24 (NKJV)
21 Jesus said to her, “Woman, believe Me, the hour is coming when you will neither on this mountain, nor in Jerusalem, worship the Father.
22 “You worship what you do not know; we know what we worship, for salvation is of the Jews.
23 “But the hour is coming, and now is, when the true worshipers will worship the Father in spirit and truth; for the Father is seeking such to worship Him.
24 “God is Spirit, and those who worship Him must worship in spirit and truth.”
The beauty of the New Covenant is that "God has granted to the Gentiles also the repentance that leads to life." (Acts 11:18)
There is no replacement.