Hebrews 11:8-10 "By faith Abraham, when he was called to go out into a place which he should after receive for an inheritiance, obeyed, and he went out, not knowing whither he went. By faith he sojourned in the land of the promise, as in in a strange country, dwelling in tabernacles with Isaac and Jacob, the heirs with him of the same promise: For he looked for a city which hath foundations , whose builder and maker is God."
Abraham went out of his country by called from God. He have faith in the Lord, he does not know where he goes. He was looking forward for a city - which have foundation- a maker is God. He was not looking forward for OLD Jerusalem on OLD earth. He was looking forward for New Jerusalem. New Jerusalem shall be descend from heaven and will land on the new earth - Rev. 21:1-2. That would be at the second advent.
In 2 Peter 3:12-13 tell us, that we are looking forward for new heavens and a new earth that would be at the coming of the Lord, not suppose 1000 years later after the second advent. Old heaven and old earth shall be pass away at the coming of the Lord - 2 Peter 3:10, 12-13.
Christ shall not reign in old present city - Jerusalem. Christ shall reign in New Jerusalem on a new earth for eternality kingdom.
Didn't you know that we are now part of Abraham's seed? In Gal. 3:14 - "That the blessing of Abraham might on the GENTILES through(what??) Jesus Christ, that we might receive the(what??) PROMISE of the the Spirit through(what??)FAITH."
It tells us, that we as Gentile Christians who already faith in Jesus Christ, we are part of the seed through Christ.
Gal 3:16 - "Now to Abraham and his seed were the promises made. He saith not, And to seeds of many; but as of ONE, And to THY SEED, WHICH IS CHRIST."
We already have faith in Jesus Christ, we are part of the seed through Jesus Christ.
Gal. 3:22 - "But the scripture hath concluded ALL under sin, (so....) that the PROMISE by(what??)FAITH of Jesus Christ might be given to them that(result of what??)BELIEVE."
It tells us, the scripture written that we are all have sinned - Romans 3:10, 23; we are doomed, BUT, that the promise given by Jesus Christ to us, through what? whosoever BELIEVE on Jesus Christ. We are saved by the faith only, not by work - Eph. 2:8-9.
Abraham was saved by believed in Christ, not by work - Gal 3:5 - "Even as Abraham believed God, and it was accounted to him for righteousness."
Apostle Paul quoted from Gen. 15:6 - "And he believed in the LORD; and he counted it to him for righteousness."
Also, Gen. 15:6 refers with Romans 4:3-5. Romans 4:3 says, "For what the scripture? Abraham believed God, and it was counted unto him for righteousness." Abraham was saved by believed on the Lord. Romans 4:4-5 says, "Now to him that worketh is the reward not reckoned of grace, but of debt. BUT to him that worketh not, but BELIEVETH on him that justifieth the undgodly, his faith is counted for righeousness."
Romans 4:3-5 tells us, Abraham was saved by BELIEVE on the Lord, not by works. Same with Eph. 2:8-9.
The plan of Ephesisans 2:8-9 have nothing change since from creation to the end of the world. The plan of the salvation never change since from creation to the end of the world. All Old Testament saints are saved by believed in the Lord, same as all New Testament saints are saved by believed in the Lord. Nothing change.
Gal. 3:26 - "For ye are ALL children of God by(what??) FAITH IN CHRIST JESUS."
It is very clear tell us, that we are ALL children of God. Even, also, ALL OLd Testament saints are children of God, whosoever faith in Jesus Christ.
There is only ONE family in the heaven. We only have ONE Father in Heaven is God. Jesus is deity as God.
Gal. 3:28-29 - "There is NEITHER Jew NOR Greek, there is NEITHER bond NOR free, there is NEITHER male NOR female: for ye are ALL ONE inChrist Jesus. And if ye be Christ's then are ye Abraham's seed, and heirs according to the PROMISE."
Gal. 3:28-29 is very clear tell us, both either Jew or Gentile who believe in Jesus Christ, ALL are ONE in Jesus Christ! So, therefore, we are part of Abraham's seed!
Therefore, all O.T. saints and N.T. saints are part in the body of Christ is the Church, because all believed in Jesus Christ through the faith only.
Is there so hard to read the scriptures about Abraham's seed?
There is none anywhere in the New Testament saying that Jews will posses the land at the second advent for the millennial kingdom. Both Jews and Gentiles who believed in Jesus Christ, they are now heirs according to the promise(Gal. 3:29).
That mean, all O.T. saints and N.T. saints will share the promise, that we shall dwell in New Jerusalem, also, on a new earth is an eternality kingdom shall be occur at the second advent.
That is simple. Is there so hard to read the scripture talk about Abraham's seed? You have to accept what the scripture saying so.
In Christ
Rev. 22:20 - Amen!