The twelve sons came from jacob who was later named israel .
And yet paul , when writing to the galations uses some real peculiar langauge . He says and the ISRAEL OF GOD .
True ISRAEL , IS OF JESUS CHRIST . and that be a fact . Its not what most want to hear .
But the ISRAEL OF GOD , are those whose faith IS IN JESUS CHRIST .
I would take that even further. Jacob was named Israel because he had overcome. Jesus is the true Israel for the same reason. Those who joined the nation or were born into the nation of Israel were called Israelites, those who join Jesus are spiritual Israelites.
It wasn’t until Jesus came on the scene in person that the title “Israel” in it’s truest spiritual sense and power could be rightly bestowed. And Mathew in particular showed this time and time again how Jesus was the fulfillment of the OT prophecies which may have originally applied to the nation, but now, according to Mathew’s inspired writings, applied in fact to Jesus. Examples are Hosea 11:1 ; Isaiah 41:8, 42:1-3.
Paul followed the same idea and reasoning by paralleling Col 1:15 with Ex 4:22, Gal 3:16 with Isaiah 41:8 and elsewhere.
Jesus Himself proclaimed Himself as the true vine, in fulfilment of Ps 80:8 which applied to the nation.
So now the mantle and authority once bestowed upon the nation has been given to Jesus. Jesus is the essence of true Israel. He only has the right to bear the name for He only has prevailed with sin and overcome. Jesus walked over the same ground that Israel walked, but came through victorious. In His temptations in the wilderness, it was appetite that came under particular scrutiny.
What Paul does in Romans and other writers in the NT however is extend that idea and show how the name Israel also now applies to Jesus’ descendants, just as it did to Jacob’s descendants. Peter also showed this when he compared the church to Exodus 19:6.(1 Peter 2:9).
So as Paul says, immediately after saying that Jesus is the ‘seed’ of Abraham, Gentile converts in Galatia were now also Abraham’s seed because they are Christ’s. They are also heirs according to the promise.
This is not ‘replacement ‘ theology. It is merely a revelation of who true Israel always was and who Israel is now. Spiritual Israel is the logical progression of his purposes. It is those people, of whatever nation kindred tongue and people, who by faith in the mercy grace and power of God overcome sin and receive Christ’s righteousness and forgiveness as a gift and are willing to share that gift with the lost. True Israel was always exclusively those who “as princes had power with God and men and prevailed”.
Thus the unfulfilled covenant that Jeremiah speaks of and repeated in hebrews, “I will place My laws in their hearts and in their minds I will write them” applies to the church, not a resurgent nation. All Israel will be saved, but the descendants of Jesus, not flesh and blood descendants of Jacob.