Ok I have to answer this question. The proof that Christians are not all Israelite is in several places in the Bible. First you must have read some of it to understand this. At the start of the church Christians were called "wayists", the term christian was at first meant as an insult. As the church began to spread to the Gentiles several problems came up. The Jewish christians were trying to tell the gentile christians that they must accept all the Jewish traditions and that included physical circumcision. For the time and the lack of medical advancement, to get cut or circumcised it was a very real chance of bleeding out, aka die. Many new gentiles left the church in fear of death. There was several other things that they disagreed on, like Jews interacting with gentiles. Keep in mind that this is in Acts 10:28, Acts 15:20,29, Acts 21:25, Romans 14:5-8, and the best Galatians 2:11-18. The problem was the difference between Jew and Gentile not Christian over non-christian. These are the same events that decided what Gentile christians had to do to practice christianity. Christians are not all Jew or hebrew and not all Jew or hebrew are all christian. The Israelite nation have been crafted over thousands of years to be who they are by God, for a reason. That reason didn't end when Christ ascended back to heaven. They still have a role to play. Again, Christians are Spiritual Israelite's not physical, and yes we have part of the promise from God, as He planned from "In the beginning". God Bless