The moment God chose Abram the Hebrew and commanded circumcision, and it was done is when ethnicity began, and distinction was made by God between Hebrew and non-Hebrew Gentile.
And that's what it all comes down to.
God never made covenant with non-Hebrew Gentiles, so they are all outside the salvation of God.
Jesus was sent to ONLY the lost sheep of the House of Israel.
He was a Jew sent to redeem the Jews. There's nothing wrong with that.
4 But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law,
5 To redeem them that were under the law, that we might receive the adoption of sons. Gal. 4:4–5.
That's the bottom line. It's their covenant. Unless you have a Jewish parent somewhere in your ancestry you are out of luck. How many passages of Scripture will you reject that say this very thing. Jesus came to redeem those who are of Abraham's seed.