"Q", I am not proposing a form of replacement theology nor am I saying that the Church is Israel. I'm stating that Paul preached on inclusion of Gentiles i.e."grafted in". Yes, we are not Jews in the flesh but by the "Spirit of Promise" or the "Spirit of G-d, were we circumcised in our hearts to know that Torah is spiritual (Romans 7:4).
Paul also said " For he is not a Jew who is one outwardly, nor is circumcision that which is outward in the flesh, but he is a Jew who is one inwardly; and circumcision is that of the heart, in the Spirit, not in the letter; whose praise is not from men but from G-d. (Romans 2:28-29). I must thank John DB, he reminded me of this scripture!
Actually, you are proposing replacement theology. You are saying that the church is Israel, if you say all who are saved are now members of Israel.
Yes, the Gentiles are grafted in, but not into Israel. The grafted in parable comes from Romans 11.
As I said, Romans is speaking alternately to Jews and Gentiles, in an attempt of reconciliation. Paul spends time explaining to the Gentiles, the place of the children of Israel/Jews in light of the New Covenant.
Romans 11:13 But I am speaking to you who are Gentiles. Inasmuch then as I am an apostle of Gentiles, I magnify my ministry,
So, in Romans 11, Paul is speaking to Gentiles concerning their place and the place of the Jewish people.
Romans 11:17 But if some of the branches were broken off, and you, being a wild olive, were grafted in among them and became partaker with them of the rich root of the olive tree
We know from what Paul said previously that most of Israel have not accepted Jesus. The branches which are broken off are Israel. Gentiles are the wild branches. If Israel is branches, then Israel is not the tree. If Gentiles were being grafted into Israel, Gentiles would have been grafted into branches which are broken off. Instead Gentiles have been grafted into the tree, alongside some Israel branches. Both Israel branches and Gentile branches are partakers of the root. The root is not Israel.
So, if Israel is the branches and not the root, what is the root? The root is Jesus, or the promises of the Messiah. Gentiles are grafted into Jesus. The Israel branches which remain on the tree are grafted into the Messiah Jesus. Sadly, most of Israel is broken off at this time.
Romans 11:12 do not be arrogant toward the branches; but if you are arrogant, remember that it is not you who supports the root, but the root supports you. 19 You will say then, “Branches were broken off so that I might be grafted in.” 20 Quite right, they were broken off for their unbelief, but you stand by your faith. Do not be conceited, but fear; 21 for if God did not spare the natural branches, He will not spare you, either. 22 Behold then the kindness and severity of God; to those who fell, severity, but to you, God’s kindness, if you continue in His kindness; otherwise you also will be cut off. 23 And they also, if they do not continue in their unbelief, will be grafted in, for God is able to graft them in again.
Gods plan for the Messiah has always included the Gentiles. It was never a plan for Israel only. One of the NT mysteries more fully explained is that God always planned to include the Gentiles in His Messianic promises.
The One New Man is only made up of people who are born again. Both Jews and Gentiles. But since this New Man is only those who are born again, is excludes both Israel and Gentiles who are not born again. It is something entirely new. A newly formed group of people who have a new nature. It might be said at this time that there are three groups of people; Jews, Gentiles and the Church (assembly) of God. This is expressed in the following verse.
1 Cor 10:32 Give no offense either to Jews or to Gentiles or to the church of God;
As far as the following verse, again, Romans is dealing with a conflict which has arisen between Jewish believers and Gentile believers, and a misunderstanding of the Gentile believers concerning the Jewish people.
For he is not a Jew who is one outwardly, nor is circumcision that which is outward in the flesh, but he is a Jew who is one inwardly; and circumcision is that of the heart, in the Spirit, not in the letter; whose praise is not from men but from G-d. (Romans 2:28-29).
This verse does not say the Gentiles are now Jews. It is talking to Gentiles about the status of the Jewish people. It is explaining the a Jewish person who has had their hearts circumcised are 'true Jews'. There are Jews who are not saved (true Jews). It does not say a Gentile becomes a Jew. It is talking about the difference between an unsaved Jew and a saved Jew.