You can have your own personal doctrine, no problem.
I am asking you whether Paul ever called us gentiles in the Body of Christ as Israel, in his letters?
Pleasure to try to be of help, please feel free to correct where the help deviates from God's scripture. God has one covenant people (some by blood, some by adoption, not including all blood descendants of Israel/Jacob, son of Isaac, son of Abraham), it is Covenant Israel (old and newly restored), it is the Church as was built upon by the Jews called Jesus / Yeshua, his disciples and the apostle Paul, who all formed the foundation block Christians, who were considered by the other Jews (sub-group of all of scattered Israel, among all the Gentiles of the earth) from the Judaic (Jewish) 'sect' of the Nazarenes. PS. Jesus / Yeshua called his apostle Peter the rock, on which he will built his Church of the new covenant with restored Israel, of the formerly destroyed Israel, under the old covenant - as God has an eternal covenant with Israel/Jacob (son of Isaac, son of Abraham), until the sun, moon and stars will be no more.
Acts 24 (ESV)
1 And after five days the high priest Ananias came down with some elders and a spokesman, one Tertullus. They laid before the governor their case against Paul.
2 And when he had been summoned, Tertullus began to accuse him, saying: "Since through you we enjoy much peace, and since by your foresight, most excellent Felix, reforms are being made for this nation,
3 in every way and everywhere we accept this with all gratitude.
4 But, to detain you no further, I beg you in your kindness to hear us briefly.
5 For we have found this man a plague, one who stirs up riots among all the Jews throughout the world and is a ringleader of the sect of the Nazarenes.
Hebrews 8 (ESV)
8 For he finds fault with them when he says: "Behold, the days are coming, declares the Lord, when I will establish a new covenant with the house of Israel and with the house of Judah,
9 not like the covenant that I made with their fathers on the day when I took them by the hand to bring them out of the land of Egypt. For they did not continue in my covenant, and so I showed no concern for them, declares the Lord.
10 For this is the covenant that I will make with the house of Israel after those days, declares the Lord: I will put my laws into their minds, and write them on their hearts, and I will be their God, and they shall be my people.
Ephesians 2 (ESV)
11 Therefore remember that at one time you Gentiles in the flesh, called "the uncircumcision" by what is called the circumcision, which is made in the flesh by hands—
12 remember that you were at that time separated from Christ, alienated from the commonwealth of Israel and strangers to the covenants of promise, having no hope and without God in the world.
13 But now in Christ Jesus you who once were far off have been brought near by the blood of Christ.
14 For he himself is our peace, who has made us both one and has broken down in his flesh the dividing wall of hostility
15 by abolishing the law of commandments expressed in ordinances, that he might create in himself one new man in place of the two, so making peace,
16 and might reconcile us both to God in one body through the cross, thereby killing the hostility.
17 And he came and preached peace to you who were far off and peace to those who were near.
18 For through him we both have access in one Spirit to the Father.
19 So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God,
20 built on the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone,
21 in whom the whole structure, being joined together, grows into a holy temple in the Lord.
22 In him you also are being built together into a dwelling place for God by the Spirit.
God's covenant with his covenant people Israel ( restored Israel in the Church of today, ruled by King David's, of the tribe of Judah's descendent King Jesus Christ / King Yeshua ha'Maschiach) last until the end of the fixed order of heaven and earth:
Jeremiah 33 (ESV)
25 Thus says the Lord: If I have not established my covenant with day and night and the fixed order of heaven and earth,
26 then I will reject the offspring of Jacob and David my servant and will not choose one of his offspring to rule over the offspring of Abraham, Isaac, and Jacob. For I will restore their fortunes and will have mercy on them."
1 Peter 1 (ESV)
1 Peter, an apostle of Jesus Christ, To those who are elect exiles of the Dispersion in Pontus, Galatia, Cappadocia, Asia, and Bithynia,
2 according to the foreknowledge of God the Father, in the sanctification of the Spirit, for obedience to Jesus Christ and for sprinkling with his blood: May grace and peace be multiplied to you.
2 Peter 1 (ESV)
1 Simeon Peter, a servant and apostle of Jesus Christ, To those who have obtained a faith of equal standing with ours by the righteousness of our God and Savior Jesus Christ:
2 May grace and peace be multiplied to you in the knowledge of God and of Jesus our Lord.
2 Peter 3 (ESV)
15 And count the patience of our Lord as salvation, just as our beloved brother Paul also wrote to you according to the wisdom given him,
16 as he does in all his letters when he speaks in them of these matters. There are some things in them that are hard to understand, which the ignorant and unstable twist to their own destruction, as they do the other Scriptures.
17 You therefore, beloved, knowing this beforehand, take care that you are not carried away with the error of lawless people and lose your own stability.