Yes we are grafted into THEIR vine, and the branches which were grafted out will be grafted back in.
Folks say "uh oh only if they believe" but they will believe, they will look upon Him whom they have pierced and mourn for Him. Israel will be saved at the coming of the Lord.
We are made co inheritors and fellow citizens of their commonwealth.
I disagree with what you wrote, Evmur.
Gentiles are grafted into Christ not the nation of Israel.
Romans 11:17
But if some of the branches were broken off, and you, being a wild olive,
were grafted in among them and became partaker with them of the rich
root of the olive tree.
The root is Christ and the Gentiles were grafted in among them and not
into Israel.
In Christ there is no Jew or Gentile.
The nation of Israel was certainly grafted out of Christ.
The letter to the Romans was written to show why Israel failed.
Romans 9:11-13
For though the twins were not yet born and had not done anything good or bad,
so that God’s purpose according to His choice would stand,
not because of works
but because of Him who calls, it was said to her, “The older will serve the younger.”
Just as it is written: “Jacob I have loved, but Esau I have hated.”
Here is where Paul explains why Israel failed.
"according to His choice would stand,
not because of works but because of Him who calls"
God's choice was salvation through faith not by works, not by legalism.
God has called everyone to be believe in His Son for righteousness and not by works.
Israel persistently pursued a path of self righteousness via legal works.
Israel can only be grafted back in, if and only if, they believe in Jesus.