11Wherefore remember, that ye being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands;
12That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:
13But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ.
14For he is our peace, who hath made both one, and hath broken down the middle wall of partition between us;
15Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace;
16And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby:
17And came and preached peace to you which were afar off, and to them that were nigh.
18For through him we both have access by one Spirit unto the Father.
19Now therefore ye are no more strangers and foreigners, but fellowcitizens with the saints, and of the household of God;
20And are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner stone;
21In whom all the building fitly framed together groweth unto an holy temple in the Lord: 22In whom ye also are builded together for an habitation of God through the Spirit.
This passage equates "the commonwealth of Israel" with "the household of God". The household of God is clearly a reference to the church, wouldn't you agree? The Gentiles in the flesh who were once "without Christ" and "aliens from the commonwealth of Israel" were "made nigh by the blood of Christ" and were then "no more strangers and foreigners, but fellowcitizens with the saints, and of the household of God". They were once aliens from the commonwealth of Israel but now they were fellowcitizens of the commonwealth of Israel. They were now Christians along with the Jewish Christ followers. The commonwealth of Israel refers to the church and only Christians are part of it. So, there is one passage that refers to Christians as being Israel or at least being a part of Israel.
Then there is this passage:
6Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:
7Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called. 8That is, They which are the children of the flesh, these are not the children of God: but the children of the promise are counted for the seed.
This passage clearly refers to two different Israels. Agree? It is saying that they are not all Israel (what I would call the Israel of God) which are of Israel (the nation of Israel). Now, is this only speaking of a subset of people from the nation of Israel and calling them Israel? What is the criteria for being part of the Israel of which not all natural Israel is part? It says "In Isaac shall thy seed be called" and "the children of the promise are counted for the seed". So, who are the children of promise who descend from Isaac? Israelites or Jews only? Or Christians in general, whether Jew or Gentile?
In Isaac shall thy seed be called
22For it is written, that Abraham had two sons, the one by a bondmaid, the other by a freewoman.
23But he who was of the bondwoman was born after the flesh; but he of the freewoman was by promise.
24Which things are an allegory: for these are the two covenants; the one from the mount Sinai, which gendereth to bondage, which is Agar.
25For this Agar is mount Sinai in Arabia, and answereth to Jerusalem which now is, and is in bondage with her children.
26But Jerusalem which is above is free, which is the mother of us all.
27For it is written, Rejoice, thou barren that bearest not; break forth and cry, thou that travailest not: for the desolate hath many more children than she which hath an husband.
28Now we, brethren, as Isaac was, are the children of promise.
29But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now.
30Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman. 31So then, brethren, we are not children of the bondwoman, but of the free.
Paul was speaking to Christians in general here and he says that we, as Isaac was, are the children of promise. In Isaac shall thy seed be called. That is referring to the spiritual seed of Isaac. That would include you and me. The heavenly Jerusalem is the mother of us all. We are all part of the heavenly Jerusalem and the heavenly Israel. As Paul said in Romans 9:8, the children of the promise are counted for the seed. Who are the children of the promise? We are. Christians.
26For ye are all the children of God by faith in Christ Jesus.
27For as many of you as have been baptized into Christ have put on Christ.
28There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
29And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise.
Notice in Romans 9:8 that it says they which are the children of the flesh (referring to natural Israelites) are not the children of God. The way that one becomes a part of the Israel which is not of Israel is not by the flesh or by one's nationality. As it says in Galatians 3:26, we are the children of God by faith in Christ Jesus. Therefore, it is faith in Christ Jesus, whether one is a natural Jew or natural Gentile, that brings us into the Israel (of God) which is not of Israel (the nation). It is by belonging to Christ that one becomes Abraham's seed, a child of the promise and a member of the Israel of God.