Friend I am not going to argue over this as we all read the Bible differently. I will tell you what I understand but I am not going to be drawn into a long argument over this
There is no one verse telling us that the Gentiles are Israel but when we put the verses together that is what I believe.
The only material I have on this matter is in Afrikaans but 119 Ministries have a good English explanation.
https://www.youtube.com/watch?v=aeQr1tD1rtI
Justin Martyr said the following:
Jesus Christ ... is the new law, and the new covenant, and the expectation of those who out of every people wait for the good things of God. For the true spiritual Israel, and the descendants of Judah, Jacob, Isaac, and Abraham (who in uncircumcision was approved of and blessed by God on account of his faith, and called the father of many nations), are we who have been led to God through this crucified Christ