And so we have one of the great ironies of the early Christian tradition. The profoundly Jewish religion of Jesus and his followers became the viciously anti-Jewish religion of later times, leading to the horrific persecutions of the Middle Ages and the pogroms and attempted genocides that have plagued the world down to recent times.6 Anti-Semitism as it has come down to us today is the history of specifically Christian reactions to non-Christian Jews. It is one of the least savory inventions of the early church.

Bart D. Ehrman