I’m going to quote Romans 9, and break it down point by point:
>So I ask, have they stumbled so as to fall? By no means! But through their trespass salvation has come to the Gentiles, so as to make Israel jealous. Now if their trespass means riches for the world, and if their failure means riches for the Gentiles, how much more will their full inclusion mean!
In other words, because Israel killed and rejected Jesus, the whole world is saved. And if rejecting Jesus caused such a marvelous gift to come to the gentiles, imagine what would happen if the Jews as a whole accepted him.
>Now I am speaking to you Gentiles. Inasmuch then as I am an apostle to the Gentiles, I magnify my ministry in order to make my fellow Jews jealous, and thus save some of them. For if their rejection means the reconciliation of the world, what will their acceptance mean but life from the dead? If the dough offered as first fruits is holy, so is the whole lump; and if the root is holy, so are the branches.
If Abraham, Issac and Jabob were holy men, then Israel as a whole shoul dascribe to the same holiness and follow God.
But if some of the branches were broken off, and you, a wild olive shoot, were grafted in their place to share the richness of the olive tree, do not boast over the branches. If you do boast, remember it is not you that support the root, but the root that supports you. You will say, “Branches were broken off so that I might be grafted in.” That is true. They were broken off because of their unbelief, but you stand fast only through faith. So do not become proud, but stand in awe.
Christians have replaced those Jews who have rejected God, but we should not be haughty about this because we could just as easily fall away from God if we lose the faith.
> For if God did not spare the natural branches, neither will he spare you. Note then the kindness and the severity of God: severity toward those who have fallen, but God’s kindness to you, provided you continue in his kindness; otherwise you too will be cut off. And even the others, if they do not persist in their unbelief, will be grafted in, for God has the power to graft them in again.
If/when Jews as a whole start converting to Christianity, we should accept them because this is an act of God.
>For if you have been cut from what is by nature a wild olive tree, and grafted, contrary to nature, into a cultivated olive tree, how much more will these natural branches be grafted back into their own olive tree. Lest you be wise in your own conceits, I want you to understand this mystery, brethren: a hardening has come upon part of Israel, until the full number of the Gentiles come in, and so all Israel will be saved;
When enough gentiles come into the fold, God will turn his spirit to soften the heart of the Jews and lead them to Christ and his church.
as it is written,
“The Deliverer will come from Zion,
he will banish ungodliness from Jacob”;
“and this will be my covenant with them
when I take away their sins.”
Prophecy from Isaiah.
>As regards the gospel they are enemies of God, for your sake; but as regards election they are beloved for the sake of their forefathers. For the gifts and the call of God are irrevocable. Just as you were once disobedient to God but now have received mercy because of their disobedience, so they have now been disobedient in order that by the mercy shown to you they also may receive mercy.
If the Jews did not Reject Jesus and his deciples, the gospel would not have spread to the whole world.
As for the modern state of Israel being in Bible prophecy, it was created whole cloth by mostly atheistic Jews in the 1800’s in order to create an enthnostate for themselves and get gentile support to do it. Their persecuting against Palestinian Christians and even non Sephardic/Ashkenazi jews shall be judged by God. All biblical prophecy about the “Return” implies it’s by God’s doing, which even a majority of Hasidic Jews agree with.