Christ says about the Old Testament: The Scriptures bear witness about me
(John 5:39). The coming of Jesus Christ as Saviour is already promised by God in Genesis 3:15. God said to the serpent (the devil): He shall bruise your head.
Someone is coming who will overcome the devil and put away all evil. We do not read any details such as the name Jesus,
the place of birth (Bethlehem), or the crucifixion, but the heart of the matter namely the gospel is clear. Adam and Eve as well as their offspring till Abraham lived with that gospel of the coming Saviour. Abraham lived with the promise of the coming Saviour. And God continued in history with Abraham and his offspring to the coming Saviour. And so God gave the blessing to Abraham (Genesis 12:2–3)! Abraham and his offspring have a special position in the history of the world: they carry with them the gospel of the coming Saviour; they live with the promise of God. And out of them God will let Jesus the Saviour be born. (In John 4:22 Jesus says, For salvation is from the Jews.
) That is why Genesis 12:3 says that in you all the families of the earth shall be blessed.
Through Abraham and his offspring—how special is that: Jesus Christ, the son of Abraham (Matthew 1:1, Galatians 3:6–9, Galatians 3:16)!
2 And I will make of you a great nation, and I will bless you and make your name great, so that you will be a blessing.