Why New Covenant theology was so dangerous- "perfidis Judaeis" the Perfidy of the Jews (1Cor.3:13-16). Since very early in Christianity (Jesus condemning Jews and abrogating the Torah) millions of Jews met their deaths as the "Christ killers" as good ol Paul would refer to them as.
Evangelicals and groups like the JWs under Rutherford and Franz would further this antisemitism. The only good Jew was a converted Jew.