Galatians 3:7-9. “Know ye therefore that they which are of faith, the same are the children of Abraham. And the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed. So then they which be of faith are blessed with faithful Abraham.”
Abraham’s seed is both physical and spiritual. God promised Abraham that, because of his faith, his seed would be as the grains of sand on the seashore, or as the stars of the heavens. Ultimately, that Seed was Jesus Christ. Physically, his seed was the nation of Israel. Spiritually, his seed is all who believe God by faith, as he did.
The scripture preached before the gospel unto Abraham: The gospel is Jesus Christ. He is the good news, the Savior of all mankind. But before the Gospel came, the scripture (the Word, promise, spoken or engraved) preached to Abraham that the entire world was to be blessed through him. Jesus was the fulfillment of that promise.
Those who believe as Abraham did, through faith in God, will be blessed with him for their faith.
Not all of Abraham’s physical seed will share in that blessing. They are his physical seed, but unless they believed God by faith, they are not his spiritual seed. That special place belongs to all who believe God by faith, and includes people of all races, all centuries, male and female, slaves and masters. Faith is the key.