How did Jews and Christians relate once the final break [of Christianity from Judaism] had come about? There are several kinds of evidence for an answer to this question, all of which point to a deterioration of relations and a rise of hostility.
The early days of the schism were marked by questioning and debate. This is clear from accounts in both rabbinic literature and the writings of the church fathers. Jews and Christians discussed such matters as the interpretation of the Hebrew Bible and the authority of their respective traditions. Even in this literature, however, one can trace the rising tensions that would ultimately prevail between the two groups.
At some point, probably connected with the Christianization of the empire in the fourth century, the Christians began to approach their Jewish neighbors with a much greater degree of antagonism, especially in Byzantine Palestine. Physical attacks against Jews and their houses of worship were not unknown in this period. Whereas in earlier times, there had been coexistence and harmony, by the fifth century much anti-Semitic legislation had been enacted. [Following the language of contemporary scholarship, “anti-Jewish” might be a more accurate term here. Anti-Semitism, a modern term, suggests a racial aspect to the hostility which was not present in the ancient world. The hostile feelings were religiously, not racially, motivated.] Jews were forbidden to build synagogues and to study the oral law. The Jews were said to be Christ‑killers, and anti‑Judaism was the norm in preaching.
In the very same period groups within the Christian church were persecuted for being “Jewish‑Christians.” In fact they were Judaizing Christians, gentiles who sought to observe Judaism as part of their Christianity because they believed in the continued authority of what they called the Old Testament. This position, declared heretical by the church, ought not to be seen as a direct continuation of the early Jewish‑Christian church of Jerusalem. These were new groups seeking to imitate what they thought the early church had been. They were not Jews by the standards of Jewish law. The old form of Jewish Christianity had disappeared.
By the end of the talmudic period, Christianity had taken up the classical anti‑Semitic views that were to inform its relations with the Jews in the Middle Ages. Jews were able to resist only by comforting themselves with the belief that they were correct and that their suffering would end with the messianic redemption. It was not until the Middle Ages, however, that the violence we have come to associate with anti‑Judaism became a significant factor.
Reprinted with permission from From Text to Tradition: A History of Second Temple and Rabbinic Judaism (Ktav).