You do not know much concerning the history of Christianity do you? The Catholic Church interprets Scripture in such a way as to divorce the Lord's church from its Hebrew foundation. Augustine of Hippo suggested that Revelation is a synopsis of the church, which all your authorities simply parrot.
Those in Christ are Abraham's offspring, heirs according to promise. What promise? The covenants (promises) God made with Abraham, David, Phineas, and the house of Israel and Judah. The New Covenant that is in the blood of the Lord is the New Covenant of Jeremiah 31. Gentile believers are grafted into the root of the natural olive (not vine) that is Abraham (the father of the Jews), Jews are not grafted into the root of a new gentile faith.
Your appeals to martyrdom and authority are both logical fallacies since Hindus, Buddhists, Muslims, as well as Christians have died for their faith and there are scholars who disagree with your scholars. The final authority is the Bible not scholars who by personal interpretations have come up with ideas that contradict the Bible.