Christianity emerged in
Roman Judea during the late
Second Temple period (first century AD), and the earliest Christians were Jews. These early Christians of Jewish origin fell into two groups: those who observed the
Jewish law and those "who felt themselves to be released from ordinances" like
Paul. The term
Jewish Christians is often reserved for the first group to distinguish those who continued Jewish practice while believing
Jesus to be the
prophesied Messiah.
Early Christianity The
Gospels record that
Jesus focused on preaching and teaching among the Jews in
Judea and
Galilee. Although he briefly visited
Samaria to speak with
Samaritans (John 4), he largely avoided ministering to
Gentiles. In one encounter with a Gentile woman, he said, "I was sent only to the lost sheep of the house of Israel" (Mt 15:24). To be sure, the
Gospel of Matthew and the
Acts of the Apostles record Jesus commissioning his followers to take his message beyond the confines of Judea after his
resurrection (Mt 28:18-20; Acts 1:8). After
Jesus's crucifixion, the focus of Christianity shifted as Gentiles were often more receptive to their message than fellow Jews. Joel Marcus writes, "As these fellow Jews came, for the most part, to reject the Christian message, while Gentiles proved astonishingly receptive to it, a problem surfaced that had not arisen before – did Gentile believers in Jesus need to convert to Judaism?" This question was debated among early Christians, and the debates would constitute some of Christianity's earliest writings. Apostles
Peter and
James were two early leaders of the Christianity who preached belief in Jesus and observance of Jewish law. The first recorded sermon by one of
Jesus's apostles is by
Peter, speaking to fellow Jews in
Jerusalem. The themes of Peter's message (see
kerygma) included the
death and
resurrection of Jesus, the fulfillment of
biblical prophecy, and the need for his Jewish audience to repent, be
baptized, and believe in Jesus for the
forgiveness of sins (Acts 2:14-36). Acts states that three thousand Jews joined the Jesus movement as a result of Peter's preaching (Acts 2:41). This number expanded to five thousand Jewish men shortly thereafter (Acts 4:4). Eventually,
James, brother of Jesus, became the leader of the Jerusalem congregation (Acts 21:17), which continued to grow through the preaching of the apostles. Around 57 CE, Acts reports that the Jerusalem congregation included at least Jewish 20,000 members (Acts 21:20, Greek: μυριάδες,
myriades), likely as a result of mission activity. Jerusalem was familiar territory to the apostles, but soon they expanded their mission beyond Judea. It is often noted that
Peter was entrusted with going on missions to Jews, and
Paul of Tarsus was entrusted with going on missions to
Gentiles (Gal 2:9). Indeed, Peter addressed one of his letters to the
Jewish diaspora (1 Pe 1:1), and Paul emphasized Gentile missions throughout the
Roman world. Paul continued to preach about Jesus to Jewish people throughout the diaspora (Acts 17-19); however, his message differed from that of Jewish Christians. Marcus writes, "Frequently throughout his ministry, then, Paul encountered Law-observant Jewish Christians, sometimes of a zealous and proselytising sort, and much of his surviving correspondence is an attempt to refute their insistence that Christians need to observe the Law." Commenting on Romans 1:16, Douglas Moo writes, "However much the church may seem to be dominated by Gentiles, Paul insists that the promises of God realized in the gospel are 'first of all' for the Jew. To Israel the promises were first given, and to the Jews they still particularly apply. Without in any way subtracting from the equal access that all people now have to the gospel, then, Paul insists that the gospel, 'promised beforehand … in the holy Scriptures' (1:2), has a special relevance to the Jew." According to Acts, Paul illustrated this continued commitment to Jewish mission by preaching in
synagogues and reasoning with Jewish people about Jesus's death and resurrection (Acts 17:2-3). He conveyed his deep desire that the Jewish people would believe in Jesus (Rom 9:1-5, 10:1), and exhorted his readers to send preachers to share the message of Jesus to the Jewish people (Rom 10:15-17). After the close of the New Testament, Christian missions to Jews continued to exist. An important second century source is the
Dialogue with Trypho of
Justin Martyr (c.140) which may be partially fictionalized, and "Trypho" may be a
cypher for rabbi
Tarfon but otherwise shows a level playing field and mutual respect as each participant appeals to the other. Many
Church Fathers contributed treatises for the purpose of Jewish mission, as surveyed by A. Lukyn Williams. Despite the prominence of Jewish Christianity alongside
Pauline (or Gentile) Christianity for a few centuries, Pauline Christianity would come to dominate the Christian world in the wake of the
Jewish-Roman wars. Marcus writes, "the first of these wars not only destroyed the temple, a unifying force for all Jews, including Jewish Christians, but it also devastated Jerusalem, the birthplace of Torah-observant Jewish Christianity." Jewish leadership shifted towards the
rabbis, and
Rabbinic Judaism "sought to define the parameters of acceptable Jewish thought and practice" to the exclusion of Christian Jews. "For all these reasons," Marcus writes, "the outreach of Christian Jews to their co-religionists became less and less effective over time." This was part of a larger historical process shaped by multiple factors resulting in an eventual split between Jewish and Christian practice.
After Constantine Emperor Constantine I brought about the end of state persecution of Christians--"imperial hostility had turned into enthusiastic support"--and the position of Christians to Jews changed. Some laws were instituted which protected the rights of Jewish converts from disinheritance, other laws also protected from abuse of the privileges of conversion from those who converted from Judaism "only for a cancellation of debt;" which suggests that in some areas of the empire local incentives to conversion existed. Accounts of conversion itself are not mentioned in rabbinical sources and are not frequent in Christian sources - excepting
Epiphanius of Salamis' account of the conversion of Count
Joseph of Tiberias, and
Sozomen's accounts of Jewish conversions in Constantinople. == Middle Ages ==