The record of the Old Testament makes clear that the Jews/Israelites are no better than other peoples.
God favours them because of the promises he made to Abraham from whom they are descended.
Israel failed to keep the covenant that God made with them at Sinai after he had brought them out of Egypt and failed to recognise their promised Messiah and had him crucified, God removed them from the promised land.
At the same time, the gospel (a New Covenant), refused by the majority of Israel, was offered to the gentiles (non-Jews).
By believing and obeying the gospel preached by Jesus Christ and his apostles, gentiles can become heirs of the promise made to Abraham.
Galatians 3:27 For as many of you as have been baptized into Christ have put on Christ. 28 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. 29 And if ye be Christ’s, then are ye Abraham’s seed, and heirs according to the promise.
The promise God made to Abraham was that of eternal inheritance on the earth, which entails resurrection from the dead and the gift of eternal life.
Genesis 13:15 For all the land which thou seest, to thee will I give it, and to thy seed for ever.
The Jews are favoured for their father’s sake.
The ‘casting off’ of Israel is temporary until the times of the gentiles are fulfilled.
Jesus said of them:
Luke 21:24 And they shall fall by the edge of the sword, and shall be led away captive into all nations: and Jerusalem shall be trodden down of the Gentiles, until the times of the Gentiles be fulfilled.
Paul writes to the Romans:
Romans 11:25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in. 26 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: 27 For this is my covenant unto them, when I shall take away their sins. 28 As concerning the gospel, they are enemies for your sakes: but as touching the election, they are beloved for the fathers’ sakes.
Ezekiel prophesies both Israel’s punishment and their future restoration
Ezekiel 36:22 Therefore say unto the house of Israel, Thus saith the Lord GOD; I do not this for your sakes, O house of Israel, but for mine holy name’s sake, which ye have profaned among the heathen, whither ye went. 23 And I will sanctify my great name, which was profaned among the heathen, which ye have profaned in the midst of them; and the heathen shall know that I am the LORD, saith the Lord GOD, when I shall be sanctified in you before their eyes. 24 For I will take you from among the heathen, and gather you out of all countries, and will bring you into your own land.
25 ¶ Then will I sprinkle clean water upon you, and ye shall be clean: from all your filthiness, and from all your idols, will I cleanse you. 26 A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh. 27 And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do them. 28 And ye shall dwell in the land that I gave to your fathers; and ye shall be my people, and I will be your God. 29 I will also save you from all your uncleannesses: and I will call for the corn, and will increase it, and lay no famine upon you. 30 And I will multiply the fruit of the tree, and the increase of the field, that ye shall receive no more reproach of famine among the heathen. 31 Then shall ye remember your own evil ways, and your doings that were not good, and shall lothe yourselves in your own sight for your iniquities and for your abominations. 32 Not for your sakes do I this, saith the Lord GOD, be it known unto you: be ashamed and confounded for your own ways, O house of Israel. 33 Thus saith the Lord GOD; In the day that I shall have cleansed you from all your iniquities I will also cause you to dwell in the cities, and the wastes shall be builded. 34 And the desolate land shall be tilled, whereas it lay desolate in the sight of all that passed by. 35 And they shall say, This land that was desolate is become like the garden of Eden; and the waste and desolate and ruined cities are become fenced, and are inhabited. 36 Then the heathen that are left round about you shall know that I the LORD build the ruined places, and plant that that was desolate: I the LORD have spoken it, and I will do it. 37 Thus saith the Lord GOD; I will yet for this be enquired of by the house of Israel, to do it for them; I will increase them with men like a flock. 38 As the holy flock, as the flock of Jerusalem in her solemn feasts; so shall the waste cities be filled with flocks of men: and they shall know that I am the LORD.
Israel are back in the land and the times of the gentiles are coming to an end. Ezekiel 38 and 39 and Zechariah 12 to 14 remain to be fulfilled before they will recognise their Messiah and be reconciled to God.
In conclusion: Israel are no better than other nations, but they have an important role in the working out of God’s purpose.
Zechariah 12:10 And I will pour upon the house of David, and upon the inhabitants of Jerusalem, the spirit of grace and of supplications: and they shall look upon me whom they have pierced, and they shall mourn for him, as one mourneth for his only son, and shall be in bitterness for him, as one that is in bitterness for his firstborn.
The kingdom of God will be the restoration of the kingdom of Israel on the earth.
Gabriel says of Jesus:
Luke 1:32 He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David: 33 And he shall reign over the house of Jacob for ever; and of his kingdom there shall be no end.
I hope you find this helpful.