The Children Of God

Romans 9:8-13 (ESV)

8 This means that it is not the children of the flesh who are the children of God, but the children of the promise are counted as offspring. 9 For this is what the promise said: “About this time next year I will return, and Sarah shall have a son.” 10 And not only so, but also when Rebekah had conceived children by one man, our forefather Isaac, 11 though they were not yet born and had done nothing either good or bad—in order that God's purpose of election might continue, not because of works but because of him who calls— 12 she was told, “The older will serve the younger.” 13 As it is written, “Jacob I loved, but Esau I hated.”

Esau can be seen as Israel in these verses. Jacob can be regarded as the Gentiles. God chose Israel among the people who dwell on the earth prepare the way for His Son and to inherit promised land. They are children of the flesh. 

The children of God are those in the kingdom of heaven who have entered His presence in the body of Christ. Their inheritance is to be like Jesus in spirit and body, the union of heaven and earth. 1Jn 3:2. 

Just as Esau served the younger son Jacob, so will Israel serve the body of Christ. The least in the kingdom of heaven is greater than any prophet of Israel. Mat 11:11.