Seems like that was addressed by Jesus himself, he began his ministry ministering to only Jews. It was only after they rejected his teaching that he began ministering to the Gentiles. He even told a parable about it; the parable of the wedding feast. Matthew 22:1-14Jesus lived and died as a devout Jew. The fact that Christians appropriated his scripture, changed the laws he lived under, and, ironically, developed a deep anti-Semitism at the same time would be shocking to him, I think.