Origins of Judaism
For centuries, the traditional understanding has been that Judaism came before Christianity and that Christianity separated from Judaism some time after the destruction of the Second Temple in 70 CE. Starting in the latter half of the 20th century, some scholars have begun to argue that the historical picture is quite a bit more complicated than that. In the 1st century, many Jewish sects existed in competition with each other, see Second Temple Judaism. The sects which eventually became Rabbinic Judaism and Early Christianity were but two of these. Some scholars have begun to propose a model which envisions a twin birth of Christianity and Judaism rather than a separation of the former from the latter. For example, Robert Goldenberg (2002) asserts that 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"".
Daniel Boyarin (2002) proposes a revised understanding of the interactions between nascent Christianity and nascent Rabbinical Judaism in Late Antiquity which views the two religions as intensely and complexly intertwined throughout this period.
Antisemitism in Christianity
Mainstream Talmudic Rabbinical Judaism today directly descends from the Pharisees whom Jesus often criticized. During Jesus' life and at the time of his execution, the Pharisees were only one of several Jewish groups such as the Sadducees, Zealots, and Essenes who mostly died out not long after the period; indeed, Jewish scholars such as Harvey Falk and Hyam Maccoby have suggested that Jesus was himself a Pharisee. Arguments by Jesus and his disciples against the Pharisees and what he saw as their hypocrisy were most likely examples of disputes among Jews and internal to Judaism that were common at the time, see for example Hillel and Shammai.