"All the promises due Israel in the OT will be fulfilled to Jew and Gentile alike, who are part of the Body of Christ, i.e., the called out ones, the chosen."
The bold portion is the correction. Thanks.
Take Romans chapters 9 through 11 and replace every instance of the words brethren, kinsmen, Israelites, Israel, Jacob, children of Israel, the Jews, people, seed, nation, seed of Abraham, remnant, olive tree, and branches with the word "church."
now do that same transformation in every book of the Bible, except for those portions which reflect poorly on "the church." Once you have done this exercise you will have the answer to your question.
Stick with the series. I think you will see your mistake as the OT promises are reviewed.