If a person will take the whole of scripture literally and lets the scripture interpret scripture with no overspiritualizing the land or the people, Israel is clearly defined in the Old and New Testaments as the two houses of Isrel and their companions. The land is a physical land, and the people are a physical people. God uses the physical and it is part of what He plans as a whole for eternity, that along with the spiritual makes a whole. Otherwise there would not be a new earth but only a new heavens to be created, as foretold to us by God in His word.
God's mystery of Romans 11 is how 10 of the 12 tribes were sifted into the Gentile nations, to come forth at the right and fulness of time as "Sons of the Living God". It was the lost sheep of the house of Israel that Jesus said He came to find and said that they would hear His voice (Hosea 1:9-11; Mat.15:24; John 10:16). We do not know but that our ancestors were related to one of those ten tribes, and probably are, but God knows, and all the prophets spend most of their time prophecying about how this mighty tribe of people would come to the aid of their brother Judah in the last days (Amos 9:9; Zech.9:13). Even the number of years within the Gentile nations that the house of Israel would be scattered is given by the prophets and a description of where they would live (Le.26:18;Ez.4:4). I have 16 pages of verses giving detail about who Israel is, and that is not even close to all that is said to them who are the "firstborn" of God, according to the promise of God to Abraham and his descendants, Isaac and Jacob. God has never changed His plan at all (Mal.3:6). From the begining, the stranger was welcome to come and sojourn with the children of Israel and be companions with them, enjoying the benefits of their covenent with God as long as they obeyed the laws of the covenant and worshipped according to the word of God. Paul says that these are, in part, the wild branches grafted in. Eventually, the jealousy and vexation between the two houses of Israel will come to an end and they will come together under One King (Is.11:13). That is the final analysis - the two houses of Israel and their companions come together under King Jesus.
Matthew 15:24 But he answered and said, I am not sent but unto the lost sheep of the house of Israel.
John 10:16 And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd.
This verse is to Israel, the house of Israel and not Judah until verse 11 where they unite under one head.
Hosea 1:9 Then God said: "Call his name Lo-Ammi, For you are not My people, And I will not be your God. 10 "Yet the number of the children of Israel Shall be as the sand of the sea, Which cannot be measured or numbered. And it shall come to pass In the place where it was said to them, You are not My people, There it shall be said to them, You are sons of the living God. 11 Then shall the children of Judah and the children of Israel be gathered together, and appoint themselves one head, and they shall come up out of the land: for great shall be the day of Jezreel.
Ezekiel confirms this reunion of the two houses and their companions and speaks of the days where they will be under one King and no longer defile themselves.
Ez. 37:16 "And you, son of man, take for yourself one stick and write on it, For Judah and for the sons of Israel, his companions; then take another stick and write on it, For Joseph, the stick of Ephraim and all the house of Israel, his companions.
17 "Then join them for yourself one to another into one stick, that they may become one in your hand.
18 "When the sons of your people speak to you saying, Will you not declare to us what you mean by these?
19 say to them, Thus says the Lord GOD, "Behold, I will take the stick of Joseph, which is in the hand of Ephraim, and the tribes of Israel, his companions; and I will put them with it, with the stick of Judah, and make them one stick, and they will be one in My hand."
20 "The sticks on which you write will be in your hand before their eyes.
21 "Say to them, Thus says the Lord GOD, "Behold, I will take the sons of Israel from among the nations where they have gone, and I will gather them from every side and bring them into their own land;
22 and I will make them one nation in the land, on the mountains of Israel; and one king will be king for all of them; and they will no longer be two nations and no longer be divided into two kingdoms.
23 "They will no longer defile themselves with their idols, or with their detestable things, or with any of their transgressions; but I will deliver them from all their dwelling places in which they have sinned, and will cleanse them. And they will be My people, and I will be their God.
24 "My servant David will be king over them, and they will all have one shepherd; and they will walk in My ordinances and keep My statutes and observe them.
25 "They will live on the land that I gave to Jacob My servant, in which your fathers lived; and they will live on it, they, and their sons and their sons sons, forever; and David My servant will be their prince forever.
The spiritual kingdom of God is invisible and within the believer, but the physical kingdom of God has not yet come to earth where it will be in the restored land of Israel which is from the river Nile to the Euphrates river in Iraq (Gen.15:18). For 1000 years the saints will reign with King Jesus and fulfill the last day of mankind on this earth - the last 1000 years or day of rest where the spear in made into a plowshare and the lion will lay with the lamb (Rev.20:1-8; 1Cor.6:2,3) The last physical dwelling of God's people is on the new earth with a new heavens, where Jerusalem is is a huge city 1400 x 1400 x 1400 miles Rev.21:16).
See where Ezekiel says we will be restored to:
Eze 37:12 Therefore prophesy and say unto them, Thus saith the Lord GOD; Behold, O my people, I will open your graves, and cause you to come up out of your graves, and bring you into the land of Israel. 13 And ye shall know that I am the LORD, when I have opened your graves, O my people, and brought you up out of your graves, 14 And shall put my spirit in you, and ye shall live, and I shall place you in your own land: then shall ye know that I the LORD have spoken it, and performed it, saith the LORD.
Zechariah sees both houses reunited with Ephraim a mighty man, ready to come home and occupy the land once again, at the whistle of God.:
Zech 10:6-10 I will strengthen the house of Judah, and will save the house of Joseph, and I will bring them back, because I have had compassion on them; and they will be as though I had not rejected them, for I am Yahweh their Elohim and I will answer them. Ephraim will be like a mighty man, and their heart will be glad as if from wine; indeed, their children will see it and be glad, their heart will rejoice in Yahweh. I will whistle for them to gather them together,for I have redeemed them; and they will be as numerous as they were before. When I scatter them among the peoples, they will remember Me in far countries, and they with their children will live and come back. I will bring them back from the land of Egypt and gather them from Assyria; and I will bring them into the land of Gilead and Lebanon until no room can be found for them.
Here, Ephraim is the arrow in Judah's bow, with the Lord fighting with them against the unbelievers with lightning at the trumpet blast. Is not this scene depicted in Revelations? How will a Church not prepared for battle participate in this?
Zech.9:13 Judah is my bow, and Israel is my arrow! Jerusalem is my sword, and like a warrior, I will brandish it against the Greeks. 14 The LORD will appear above his people; his arrows will fly like lightning! The Sovereign LORD will sound the trumpet; he will go out against his enemies like a whirlwind from the southern desert. 15 The LORD Almighty will protect his people, and they will subdue their enemies with sling stones. They will shout in battle as though drunk with wine, shedding the blood of their enemies. They will be filled with blood like a bowl, drenched with blood like the corners of the altar.
Oh for the day that this verse would be fulfilled. Today, it seems so far off as Ephraims descendants do not recognize their heritage and Judah its Messiah:
Isaiah 11:13 The envy also of Ephraim shall depart, and the adversaries of Judah shall be cut off: Ephraim shall not envy Judah,and Judah shall not vex Ephraim.
Here, Amos speaks after Hosea's prophecy towards Ephraim and the house of Israel. Indeed, God has sifted us into all the nations as though we were not His people, but has called us out as "Sons of the Living God".
Amos 9:9 "For surely I will command, And will sift the house of Israel among all nations, As grain is sifted in a sieve; Yet not the smallest grain shall fall to the ground.
Hosea 1:9 Then God said: "Call his name Lo-Ammi, For you are not My people, And I will not be your God. 10 "Yet the number of the children of Israel Shall be as the sand of the sea, Which cannot be measured or numbered. And it shall come to pass In the place where it was said to them, You are not My people, There it shall be said to them, You are sons of the living God.
Hosea 5:3 I know Ephraim, and Israel is not hid from me: for now, O Ephraim, thou committest whoredom, and Israel is defiled.
Hosea 8:8 ¶ Israel is swallowed up; Now they are among the Gentiles Like a vessel in which is no pleasure.
The house of Judah came back and rebuilt the temple and walls of Jerusalem after a time, never giving up their identity to God, but the house of Israel never repented of their sins and forgot their God altogether, following the sin of Jeroboam, their first king. Jeroboam changed the feasts and appointed times God has set so that the people would not yearn for their brother and the solemn assemblies of God, being political and wicked instead of obeying God.
Ezekiel 4:4 Lie thou also upon thy left side, and lay the iniquity of the house of Israel upon it: according to the number of the days that thou shalt lie upon it thou shalt bear their iniquity. 5 For I have laid upon thee the years of their iniquity, according to the number of the days, three hundred and ninety days: so shalt thou bear the iniquity of the house of Israel. 6 And when thou hast accomplished them, lie again on thy right side, and thou shalt bear the iniquity of the house of Judah forty days: I have appointed thee each day for a year.
Le 26:18 And if ye will not yet for all this hearken unto me, then I will punish you seven times more for your sins.
All the prophets speak of the physical land of Israel and the restoration to it. The verses are too many to share by posting. I can only recommend rereading the Old Testament as I have had to do once learning that nearly all I was taught regarding "Israel" was wrong.
Is.65:9 I will preserve a remnant of the people of Israel and of Judah to possess my land. Those I choose will inherit it and serve me there. 10 For my people who have searched for me, the plain of Sharon will again be filled with flocks, and the valley of Achor will be a place to pasture herds.
Jer 3:18 In those days the house of Judah will walk with the house of Israel, and they will come together from the land of the north to the land that I gave your fathers as an inheritance.
Micah 4:6-8 In that day, declares Yahweh, I will assemble the lame and gather the outcasts, Even those whom I have afflicted. I will make the lame a remnant and the outcasts a strong nation. And Yahweh will reign over them in Mount Zion from now on and forever. As for you, tower of the flock, hill of the daughter of Zion, to you will come - even the former dominion will come, the kingdom of the daughter of Jerusalem.