“In you all the families of the earth shall be blessed.” (Genesis 12:3)
You who hope in Christ and follow him in the obedience of faith are Abraham’s descendants and heirs of his covenant promises.
God said to Abraham in Genesis 17:4, “Behold, my covenant is with you, and you shall be the father of a multitude of nations.” But Genesis makes plain that Abraham did not father a multitude of nations in a physical or political sense. Therefore, the meaning of God’s promise was probably that a multitude of nations would somehow enjoy the blessings of sonship even though physically unrelated to Abraham.
That’s no doubt what God meant in Genesis 12:3 when he said to Abraham, “In you all the families of the earth shall be blessed.” From the very beginning, God had in view that Jesus Christ would be the descendant of Abraham and that everyone who trusts in Christ would become an heir of Abraham’s promise. Paul says in Galatians 3:29, “If you are Christ’s, then you are Abraham’s offspring, heirs according to promise.”
So, when God said to Abraham 4,000 years ago, “Behold, my covenant is with you, and you shall be the father of a multitude of nations,” he opened the way for any one of us, no matter what nation we belong to, to become a child of Abraham and an heir of God’s promises. All we have to do is share the faith of Abraham — that is, bank our hope on God’s promises, so much so that, if obedience requires it, we could give up our dearest possession like Abraham gave up Isaac.
We don’t become heirs of Abraham’s promises by working for God, but by being confident that God works for us. “[Abraham] grew strong in his faith as he gave glory to God, fully convinced that God was able to do what he had promised” (Romans 4:20–21). That’s why Abraham could obey God even when obedience looked like a dead-end street. He trusted God to do the impossible — like raise his son from the dead.
Faith in God’s promises — or today we would say, faith in Christ, who is the confirmation of God’s promises — is the way to become a child of Abraham; obedience is the evidence that faith is genuine (Genesis 22:12–19). Therefore, Jesus says in John 8:39, “If you were Abraham’s children, you would be doing the works Abraham did.”
Children of Abraham are people from all nations who put their hope in Christ and, like Abraham on Mount Moriah, therefore don’t let the loss of their most precious earthly possession stop their obedience.
You who hope in Jesus Christ and follow him in the obedience of faith are the descendants of Abraham and heirs of his covenant promises.