Israel was in fact "dead" when they were created by God. No man has life except they eat of His flesh and drink of His blood, or in other words, believe on Jesus Christ, the bread of Heaven which came down that men might have life, and thus not be dead.
Prophecy continually makes it clear that God is not finished with Israel. Their restoration is a major theme of Prophecy, and we will see it fulfilled just as all Prophecy is fulfilled.
Nowhere in Prophecy is Israel said to be destroyed (except in the context of their spiritual condition, which is one of utter destruction that is shared by all men since the Fall). It is the Jew and the Gentile that are made one in Christ, not former Jews and Gentiles.
We don't see 144,000 Gentile witnesses in the Tribulation, but those distinctly identified as tribes of Israel.
No, God is not yet done with Israel, and He will bring them under the New Covenant through their final Week of judgment, the Tribulation.
God bless.
Israel is dead nationally and collectively because they are separated from God and by 70 AD, ending their probationary period, they had failed to enter into their rest and was subsequently buried in the graveyard of the nations. They lost their national identity and came under the control and authority of the governments of the nations into which they were driven. For good measure God destroyed their temple and burned down their city. They were not born again under the grace of God, a requirement for the physical kingdom of Jesus Christ to be established on the earth. It was at this point that the church of Jesus Christ took on a distinctively gentile character. A Jew outside of his land is a stranger and is cut off from his national covenants. Hebrews was written in circa 65 AD, long after the church of Jesus Christ had been established at the Pentecost of Acts 2 when the Spirit was sent to Israel in 30 AD.
In Romans 7 through 11 (written in AD 58) Paul deals with Jews as the children of Abraham by birth and connected to God in covenant relationship but it is explained to them that this birth does not make them children of God. Therefore Israel is divided at this stage into two groups. The natural, those born of Abraham, and the spiritual, those born of Abraham first and then born again of God and the figures and types, such as Esau and Jacob, and Ishmael and Isaac are intended to contrast this truth and to give a physical example that should be easy to follow for those familiar with these people and their heritage. The first born is natural and the second born is the one suited for God to bless.
We learn that the larger group,the natural, seeks righteousness by the works of the law while those who are spiritual have received the righteousness of Christ, which is perfect and is that which is required by God, by faith in what he has accomplished in his life, death, and resurrection on their behalf. Further along, we learn that both have designated titles. The natural among them are called Israel and the spiritual are designated as the "remnant (of Israel) according to the election of grace." Since Israel, the larger group, are blinded by their own unbelief and only a small number believes, God includes the gentiles so, as he says in Romans 11, "his house might be full." It is important to see that it was God's intention to fashion a family or house for Jesus Christ in this age.
Heb 3:1 Wherefore, holy brethren, partakers of the heavenly calling, consider the Apostle and High Priest of our profession, Christ Jesus;
2 Who was faithful to him that appointed him, as also Moses was faithful in all his house.
3 For this man was counted worthy of more glory than Moses, inasmuch as he who hath builded the house hath more honour than the house.
4 For every house is builded by some man; but he that built all things is God.
5 And Moses verily was faithful in all his house, as a servant, for a testimony of those things which were to be spoken after;
6 But Christ as a son over his own house; whose house are we, if we hold fast the confidence and the rejoicing of the hope firm unto the end.
The personal pronouns in this letter are Hebrews, and does not include gentiles, and we know now that the Hebrews, the holy brethren, did not answer the heavenly call and fell away and according to Hebrews 6 and 10 it was impossible to renew them again to repentance. The end here is obviously the end of the 40 years probationary period, which was quickly coming upon them, and they did not enter into God's rest.
Heb 1:1 God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets,
2 Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds (aions = ages);
What did the Son say to the Hebrews in these last days?
Mt 11:28 Come unto me, all ye that labour and are heavy laden, and I will give you rest.
29 Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls.
30 For my yoke is easy, and my burden is light.
It is important to know that God deals with his Hebrew people as a single entity though they as a people are many individuals. Their second birth will be as the natural birth. Every single Hebrew was delivered out of Egypt. The first passover was the birth of their nation and the beginning of months.
What advice did the author of Hebrews give concerning what they had heard the Son say?
Heb 2:1 Therefore we ought to give the more earnest heed to the things which we have heard, lest at any time we should let them slip.
Back to the unpardonable sin.
We see in Hebrews that Jesus kept his word to Israel who rejected him when he came.
Mt 12:32 And whosoever speaketh a word against the Son of man, it shall be forgiven him: but whosoever speaketh against the Holy Ghost, it shall not be forgiven him, neither in this world, neither in the world to come.
Jesus spoke to Israel in the last days of the age of the law. The end of this present age could have ended in 70 AD had the Hebrews repented and believed the gospel. The Romans would have brought all the OT prophecies concerning the end times to pass and the saying of Jesus would have found its truth that these Jews would not have been saved in the present age. This brings me to the prophesies concerning the group that is titled "Israel" in Romans 11. They will be saved in the age called "the day of the Lord," the next age, which is very near.
When the house is full then the bridegroom will come and take his bride the church to the Father's house in heaven and the resurrected nation of Israel will become the focus of the Father's salvation activity and the fulfillment of every prophecy concerning his kingdom and his people will be minutely fulfilled down to the jot and tittle. All Israel (those few that are left after the great tribulation) will then be saved and Jesus Christ will reign on the earth in perfect righteousness for one thousand years.
So says the scriptures.
Ro 11:5 Even so then at this present time also there is a remnant according to the election of grace.
Ro 11:7 What then? Israel hath not obtained that which he seeketh for (which is righteousness); but the election hath obtained it, and the rest were blinded
Ro 11:11 I say then, Have they stumbled that they should fall? God forbid: but rather through their fall salvation is come unto the Gentiles, for to provoke them to jealousy.
12 Now if the fall of them be the riches of the world, and the diminishing of them the riches of the Gentiles; how much more their fulness?
13 For I speak to you Gentiles, inasmuch as I am the apostle of the Gentiles, I magnify mine office:
14 If by any means I may provoke to emulation them which are my flesh, and might save some of them.
15 For if the casting away of them be the reconciling of the world, what shall the receiving of them be, but life from the dead?
Life from the dead is a resurrection in anyone's vocabulary. So Israel will receive a resurrection and we saw it in 1948 AD. But they were resurrected in body but the Spirit is not in them yet, but look at this.
Ro 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 (this is the Israel that was blinded and dead)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.
29 For the gifts and calling of God are without repentance.
See Ezekiel's dry bone vision in chapters 36 & 37 for explanation.