For nearly four millennia Judaism was essentially a unified religious system based on shared traditions. Despite the emergence of various sub-groups through the centuries such as the Sadducees, Pharisees, Essenes, Karaites, Shabbateans and Hasadim, Jewry was united in the belief in a providential God who had chosen the Jews as his special people and given them a code of law.

In the modern period, however, the Jewish religion has fragmented into a series of separate denominations with competing ideologies and theological views. Despite the creation of the State of Israel, the Jewish...