Now the promises were spoken to Abraham and to his seed. It doesn’t say, “and to seeds,” as of many, but as of one, “and to your seed,” who is the Messiah.
He took him outside and said, “Look up now, at the sky, and count the stars—if you are able to count them.” Then He said to him, “So shall your seed be.”
But God said to Abraham, “Do not be displeased about the boy and your slave woman. Whatever Sarah says to you, listen to her voice. For through Isaac shall your seed be called.
The scepter will not pass from Judah, nor the ruler’s staff from between his feet, until he to whom it belongs will come. To him will be the obedience of the peoples.
You are the sons of the prophets and also of the covenant that God cut with your fathers, saying to Abraham, ‘In your seed shall all the families of the earth be blessed.’
For this reason it depends on trust, so that the promise according to grace might be guaranteed to all the offspring—not only to those of the Torah but also to those of the faith of Abraham. He is the father of us all
Then why the Torah? It was added because of wrongdoings until the Seed would come—to whom the promise had been made. It was arranged through angels by the hand of an intermediary.
The Scriptures, foreseeing that God would justify the Gentiles by faith, proclaimed the Good News to Abraham in advance, saying, “All the nations shall be blessed through you.”
He is not holding fast to the Head. It is from Him that the whole body, nourished and held together by its joints and tendons, grows with a godly increase.