Emergence as separate religious communities
During the early first century CE there were many competing Jewish sects in the Holy Land, and those that became Rabbinic Judaism and Proto-orthodox Christianity were but two of these. There were Pharisees, Sadducees, and Zealots, but also other less influential sects, including the Essenes. The first century BCE and first century CE saw a growing number of charismatic religious leaders contributing to what would become the Mishnah of Rabbinic Judaism; and the ministry of Jesus, which would lead to the emergence of the first Jewish Christian community.
Historians continue to debate the precise moment when early Christianity established itself as a new religion, apart and distinct from Judaism. It is difficult to trace the process by which the two separated or to know exactly when this began. Jewish Christians continued to worship in synagogues together with Jews for centuries. Some scholars have found evidence of continuous interactions between Jewish-Christian and Rabbinic movements from the mid-to late second century CE to the fourth century CE. Philip S. Alexander characterizes the question of when Christianity and Judaism parted company and went their separate ways as "one of those deceptively simple questions which should be approached with great care."
According to historian Shaye J. D. Cohen, "the separation of Christianity from Judaism was a process, not an event," in which the church became "more and more gentile, and less and less Jewish."[note 1]
According to Cohen, early Christianity ceased to be a Jewish sect when it ceased to observe Jewish practices, such as circumcision.
According to Robert M. Price, early Christianity and Javneh-Rabbinic Judaism had their own developmental trajectories, rather than separating in a formal way.[note 2]
Talmudist and professor of Jewish studies Daniel Boyarin proposes a revised understanding of the interactions between nascent Christianity and Judaism in late antiquity, viewing the two "new" religions as intensely and complexly intertwined throughout this period. According to Boyarin, Judaism and Christianity "were part of one complex religious family, twins in a womb," for at least three centuries.[note 3] Alan Segal also states that "one can speak of a 'twin birth' of two new Judaisms, both markedly different from the religious systems that preceded them."[note 4]
Dating of separation
According to Cohen, this process ended in 70 CE, after the great revolt, when various Jewish sects disappeared and Pharisaic Judaism evolved into Rabbinic Judaism, and Christianity emerged as a distinct religion. Other scholars argue that Christians and Pharisees broke decisively only after the Bar Kokhba's revolt, when the successors of the Pharisees claimed hegemony over all Judaism, and – at least from the Jewish perspective – Christianity emerged as a new religion.
Yet, according to Robert Goldenberg, it is increasingly accepted among scholars that "at the end of the 1st century CE there were not yet two separate religions called 'Judaism' and 'Christianity'".[note 5]