Jewish Christians were the followers of a Jewish religious sect that emerged in Judea during the late Second Temple period. These Jews believed that Jesus was the prophesied Messiah and they continued their adherence to Jewish law. Jewish Christianity is the foundation of Early Christianity, which later developed into Catholic and Eastern Orthodox Christianity. Christianity started with Jewish eschatological expectations, and it developed into the worship of Jesus as the result of his earthly ministry, his crucifixion, and the post-crucifixion experiences of his followers. Modern scholars are engaged in an ongoing debate about the proper designation of Jesus' first followers. Many modern scholars believe that the term Jewish Christians is anachronistic given the fact that there is no consensus about the date of the birth of Christianity. Some modern scholars have suggested that the designations "Jewish believers in Jesus" and "Jewish followers of Jesus" better reflect the original context.

Jewish religious movements, sometimes called "denominations", include diverse groups within Judaism which have developed among Jews from ancient times. Today in the west, the most prominent divisions are between traditionalist Orthodox movements and modernist movements such as Reform Judaism originating in late 18th century Europe, Conservative originating in 19th century Europe, and other smaller ones, including the Reconstructionst and Renewal movements which emerged later in the 20th century in the United States.