You are failing to differentiate between "we" and "they."
There is no us or they. There is only Christ. Christ is the heir to the promises of God.
Now the promises were made to Abraham and to his offspring. It does not say, “And to offsprings,” referring to many, but referring to one, “And to your offspring,” who is Christ.
Galatians 3:16
The only reason we inherit anything is because we are a part the body of Christ
There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus. And if you are Christ's, then you are Abraham's offspring, heirs according to promise.
Galatians 3:28-29
And apart from the body of Christ, no one inherits anything, not even th Old Testament saints.
And all these, though commended through their faith, did not receive what was promised, since God had provided something better for us, that apart from us they should not be made perfect.
Hebrews 11:39-40
But the Lord has made explicitly stated promises to the nation of Israel, as well a to its sub-nations of Judah and Ephraim, and to each of the twelve tribes of Israel individually, as well as to the physical land of Israel and to the city of Jerusalem, and to numerous individuals from that nation.
God fulfilled his land promise to the 12 tribes of Israel under the old covenant
Thus the Lord gave to Israel all the land that he swore to give to their fathers. And they took possession of it, and they settled there.
Joshua 21:43
The old covenant was never meant to be permanent. It was only a picture of Christ meant to guide the Israelites and show them the greater spiritual promises that are found in Him.
For since the law has but a shadow of the good things to come instead of the true form of these realities, it can never, by the same sacrifices that are continually offered every year, make perfect those who draw near.
Hebrews 10:1
These are a shadow of the things to come, but the substance belongs to Christ.
Colossians 2:17
And the old covenant did pass away
In speaking of a new covenant, he makes the first one obsolete. And what is becoming obsolete and growing old is ready to vanish away.
Hebrews 8:13
The physical land of the promise was only a picture of the true heavenly land that we now come to.
But as it is, they desire a better country, that is, a heavenly one. Therefore God is not ashamed to be called their God, for he has prepared for them a city.
Hebrews 11:16
But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to innumerable angels in festal gathering,
Hebrews 12:22
Now Hagar is Mount Sinai in Arabia; she corresponds to the present Jerusalem, for she is in slavery with her children. But the Jerusalem above is free, and she is our mother. But what does the Scripture say? “Cast out the slave woman and her son, for the son of the slave woman shall not inherit with the son of the free woman.” So, brothers, we are not children of the slave but of the free woman.
Galatians 4:25-26,30-31
It is never the natural that is second. Just as the body is first natural and then secondly spiritual, so the promises of God. He did fulfill the promises physically under th old covenant with Israel. But this is only a picture of the greater spiritual realities, of which God fulfills in Christ.
But it is not the spiritual that is first but the natural, and then the spiritual.
1 Corinthians 15:46
God often uses earthly things as a picture of greater spiritual truths. If we don’t understand these earthly pictures, how can we ever understand the heavenly reality.
If I have told you earthly things and you do not believe, how can you believe if I tell you heavenly things?
John 3:12
