Nothing to address. Romans 11:13-27 is supportive of the OP and that is that gentile believers are now grafted in with Jewish believers and we are all one in Christ. God's true Israel in the new covenant according to the scriptures are not longer those born of the flesh of the seed of Abraham but are now all those who are born of the Spirit into God's new covenant promise by faith to believe and follow Gods' Word *Romans 9:6-8; Galatians 3:27-28; Romans 2:28-29; John 3:3-7; Hebrews 8:10-12 from Jeremiah 31:31-34 and Ezekiel 36:24-27. If you are not a part of God's true Israel then you have no part in God's new covenant promise. God never made the new covenant to gentiles. Romans 11:13-27 is used in the last link in the OP as support scriptures for God's true Israel.
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ROMANS 11:16-27
[16], For if the first-fruit are holy, the lump is also holy: and IF THE ROOT IS HOLY, SO ARE THE BRANCHES.
The root represents Christ...
[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 PARTAKE OF THE ROOT AND FATNESS OF THE OLIVE TREE.
The Jewish and the Gentile believers are the branches grafted onto the root (Christ)...
[18], Boast not against the branches. But if you boast, you bear not the root, but the root you.
[19], You will say then, THE BRANCHES WERE BROKEN OFF, THAT I MIGHT BE GRAFTED IN.
[20], Well; BECAUSE OF UNBELIEF THEY WERE BROKEN OFF, AND YOU STAND BY FAITH. Be not arrogant, but fear:
God's ISRAEL are all those who believe and follow god's word...
[21], For IF GOD SPARED NOT THE NATURAL BRANCHES, TAKE HEED LEST HE ALSO NOT SPARE YOU.
[22], Behold therefore the goodness and severity of God: on them who fell, severity; but toward you, goodness, IF YOU CONTINUE IN HIS GOODNESS: OTHERWISE YOU ALSO SHALL BE CUT OFF.
[23], And they also, IF THEY ABIDE NOT STILL IN UNBELIEF, SHALL 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 GOOD OLIVE TREE: HOW MUCH MORE SHALL THESE, WHO ARE THE NATURAL BRANCHES, BE GRAFTED INTO THEIR OWN OLIVE TREE?
[25], For I would not, brethren, that you should be ignorant of this mystery, lest you should be wise in your own conceits; that blindness in part is happened to Israel, UNTIL THE FULLNESS OF THE GENTILES COMES IN.
[26], And so ALL ISRAEL SHALL BE SAVED: AS IT IS WRITTEN, THERE SHALL COME OUT OF ZION THE DELIVERER, AND SHALL TURN AWAY UNGODLINESS FROM JACOB:
The NEW COVENANT is for both Jews and Greek, bond and free, all those who are in Christ. All in Christ are the seed of Abraham and heirs according to the promise.
[27], FOR THIS IS MY COVENANT UNTO THEM, WHEN I SHALL TAKE AWAY THEIR SINS.
Gentiles are now grafted in to God's ISRAEL. If you are not a part of God's ISRAEL you have no part in the NEW COVENANT.
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GALATIANS 3:28-29 [28], THERE IS NEITHER JEW NOR GREEK, there is neither bond nor free, there is neither male nor female: FOR YOU ALL ONE IN CHRIST JESUS AND IF YOU BE CHRISTS, THEN YOU ARE ABRAHAM'S SEED FOR YOU ARE ALL ONE IN CHRIST JESUS [29], and IF YOU BE CHRISTS, THEN ARE YOU ABRAHAM'S SEED, AND HEIRS ACCORDING TO THE PROMISE.
ROMANS 9:6-8 [6], FOR THEY ARE NOT ALL ISRAEL WHICH ARE OF ISRAEL,: [7], NEITHER, BECAUSE THEY ARE THE SEED OF ABRAHAM, ARE THEY ALL CHILDREN: but in Isaac shall thy seed be called <Christ> [8], That is, THEY WHICH ARE THE CHILDREN OF THE FLESH, THESE ARE NOT THE CHILDREN OF GOD: BUT THE CHILDREN OF THE PROMISE <those who believe> ARE COUNTED FOR THE SEED.
God's ISRAEL are all those in CHRIST that have been given a NEW HEART according to the NEW COVENANT promise...
ROMANS 2:28-29 [28], FOR HE IS NOT A JEW WHICH IS ONE OUTWARDLY; NEITHER IS THAT CIRCUMCISION, WHICH IS OUTWARDS IN THE FLESH: [29], BUT HE IS A JEW WHICH IS ONE INWARDLY; and CIRCUMCISION IS OF THE HEART, IN THE SPIRIT, AND NOT IN THE LETTER; whose praise is not of men, but of God.
In the NEW COVENANT all those in Christ are now God's ISRAEL...
COLOSSIANS 3:11 [11], WHERE THERE IS NEITHER JEW NOR GREEK circumcision nor uncircumcision, Barbarian, Scythian, bond nor free: BUT CHRIST IS ALL IN ALL.
Take Care.