WHO ARE THE PEOPLE OF GOD?
Israel in the Old Testament very much saw themselves as the people of God. It was to them that the promises of salvation were made. The covenants, the temple, the Law. But even within Israel, there was only a remnant of what we would call "True Israelites". To make the point who entered the land flowing with milk and honey? Was it that generation which God brought out by his mighty hand from Egypt. No from that generation only 2 entered. It was the generation of their children who inherited what was promised. It was only those who trusted in God to do as he had promised, that entered.

We find the unbelieving generation to say things like "God has brought us out of Egypt, to die" What a slap in the face of God. This however was proof that they weren't persuaded that God was able to do what he had promised to do. Again just before they were to enter the land, when they heard the reports of the spies about the giants and the walled cities. Again they said "God has brought us here so that the Amorites may kill us." No wonder God was displeased and made them wonder in exile, in the desert for forty years. This shows us that not all who are called Israel, are a people of faith. Therefore not all who are Israel are the people of God.
The generation that came after them, was a believing generation. They inherited the promise of the land because they believed God would do as he promised. But God warned them that if they rebelled, they would suffer the same fate as their fathers. They would be exiled from the land. The curses of the law would come upon them, and God would put foreign rulers over them. But if they returned to the Lord with all their heart, God would restore their fortunes. History tells us all that happened. Paul in Romans 9-11 sums it up for us. He says "God held his hand out to an obstinate people all day long." Israel's history was in the main, the history of a pagan people. A nation of idolaters, hard of heart, and stiff necked. Of course there are exceptions to this rule. There was always a remnant who were faithful to their God. The answer is clear, "not all who are called Israel are the Israel of God." Paul goes to great lengths to show that circumcision in the flesh is of no value. What is of value is the circumcision of the heart.