what will happen to the Jews?

[Clare73]

Incorrect.

The new covenant is still with genetic Israel, aka, the HOUSE OF ISRAEL,

The New Covenant in the blood of Jesus Christ (1Co 11:25) is with those who believe in and trust on his sacrificial atoning blood (Ro 3:25) for the remission of their sin and right standing (justified; i.e., "not guilty") with God (Ro 3:24).

Many among genetic Israel (by bloodline) are not in the New Covenant.

and we gentiles have to be grafted onto their covenant, by faith, per Romans 11.

We are grafted into the one olive tree (Ro 11:17), the Church, consisting of both OT saints (Heb 12:22-23) and NT saints.

Jer 31:31 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 all Israel is (true) Israel (Ro 9:6), only those regenerated (born again) by the power of the Holy Spirit within (Ro 2:28-29) are true Israel.

God has not forsaken national Israel:

Not totally. . .there has always been a faithful remnant.

Rom 11:1 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.

Rom 11:2 God hath not cast away his people which he foreknew

"his people which he foreknew" (chosen as objects of his love--Dt 7:7-8)

God not only knew his people before they had any knowledge of him, but he also knew them in the sense of choosing them by his grace before the foundation of the world (Eph 1:4)

Wot ye not what the scripture saith of Elias? how he maketh intercession to God against Israel, saying,

Scripture after scripture in prophetical Old Testament books, says
God will gather Israel from all over the world where He scattered them, bring them back to the land He gave them,

Fulfilled in the return from exile, where the Temple was rebuilt, the walls were rebuilt, the people confessed their sin and entered into a binding agreement of faithfulness, worship was restored (Neh 7:73b-10:39) and idolatry was never again seen in Israel.

and they will remain there forever.

God's promise of an everlasting inheritance is not a promise of earthly land, but a promise of heavenly land in the heavenly city (Heb 11:13-16).
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