Acher

Originally known as Elisha ben Abuyah, the mentor of the famed Rabbi Meir was profoundly troubled by the horrific events of his time, much as people today question the Holocaust. Rejecting the concept of reward in the next world, Elisha abandoned Jewish observance, openly committing many transgressions to demonstrate his disbelief. As such, he became known as Acher, the Other One, due to his radical change of heart. Although Rabbi Meir kept a connection to his erstwhile mentor, other sages ostracized him, and Acher became the prime example of a great Torah scholar gone astray.

Breakoff of the Christians

The original Christians were Jews who acted Jewishly in all respects except for their belief in Yeshu. Eventually, the Christians realized that the Jewish people would not accept their idolatrous beliefs, and decided to introduce their religion to the Gentile world. Instrumental in this endeavor was a Jew named Paul, with whom the major tenets of Christianity originate. In order to make Christianity palatable to non-Jews, Paul taught that the Torah's commandments do not have to be kept; instead, faith in Yeshu was all that mattered.

Paul traveled all over the Roman Empire, attracting many converts to Christianity, a new religion which borrowed ideas from the Torah, some of its morals and ethics, and some rituals, which Paul combined with pagan rites. Not content with rewriting basic Judaism, Paul also claimed that the gentile Christians supplanted the Jews as G‑d's chosen people, and that the Christian New Testament had replaced the Torah. He also taught that the Jews killed Yeshu and could only be saved only if they turn to his worship. Such teachings, although not the sole basis for Christian anti-Semitism, played a significant role in the way post-Pauline Christians viewed the Jewish people. As two scholars put it:

“Those who believe Paul taught such ideas are able to cite many passages from his own writings in support of their interpretation. If they are right, he must be held responsible for the theological anti-Judaism that soon grew up in the Church and proved to be the ancestor of later anti-Semitism. In any case, since his writings so eloquently set forth the Christian myth, inherently anti-Jewish as it turned out to be, he can hardly escape all responsibility for the implications that later generations found in it."

"So when it comes to the question of the origin of Christian hatred for Jews, Paul is at the story's center. His letters, as the oldest extant Christian writings, show him at his most flawed. His rage, prejudice, and self-obsession are as evident as his courage, gentleness, and faith."

By 100 CE, Christianity was an exclusively non-Jewish religion.