The Jewish philosopher Moses Maimonides (1135-1204 C.E.), known as the Rambam, is considered to be one of the greatest medieval philosophers, exercising significant influence in both the Jewish and Gentile world of his day - an influence that continues into the present. Maimonides was the first person to write a systematic code of Jewish law.
Maimonides encapsulated Judaism with his thirteen principles of Jewish faith which originally appeared in his commentary on Mishnah Sanhedrin. They are found in one form or another in virtually every prayer book, and form the basis for Yigdal, the well-known synagogue hymn. While there is no universally-accepted, definitive statement of Jewish belief, Maimonides’ thirteen principles are widely accepted as standard Jewish belief.
For those interested in a summarization of Maimonides’ discussion of these principles, I recommend Maimonides’ Principles: The Fundamentals of Jewish Faith by Aryeh Kaplan (2002 reprint) first published by the National Conference of Synagogue Youth of the Orthodox Union. Kaplan has provided a readable treatment of the thirteen principles, thus perpetuating what Maimonides surely desired when he first wrote them: providing access to all Jews, educated or uneducated, access to the basic tenets of Jewish faith and responsibility.
Among those principles is one concerning the Jewish hope of a Messiah. Principle 12 reads:
I believe with perfect faith in the coming of the Messiah. How long it takes, I will await his coming every day.
Including Jesus of Nazareth, whom Christians (and I am one) believe is the Messiah promised by the Hebrew propehts, there have been, according to Jerry Rabow, at least fifty persons who have claimed messianic credentials. However, the vast majority of Jews today still patiently wait the coming of their Messiah who will defeat Israel’s enemies, restore her to the land of Israel and usher in worldwide peace.
The latest messianic claim originates in the Lubavitch Hasidim movement which sees the late Menachem Mendel Schneerson (1902-1994) as the promised Messiah. Rebbe Schneerson is the seventh leader of the Lubavitch Hasidic branch of Judaism. Many of his followers believe that Rebbe Schneerson will one day rise from the dead and complete his messianic mission.
It is this belief that has David Berger on a mission to have messianist Lubavitchers decredentialed, so to speak. In The Rebbe The Messiah and the Scandal of Orthodox Indifference (Littman Library of Jewish Civilization, 2001), Berger issues a no-holds-barred 
challenge to the Orthodox community to face up to the problem created by Lubavitchers attributing messiahship to Schneerson. He believes that the rise of Lubavitch messianism has given credence to two propositions from which “every mainstream Jew in the last millennium would have instantly recoiled.” Those two options are:
1. A specific descendant of King David may be identified with certainty as the Messiah even though he died in an unredeemed world. The criteria always deemed necessary for a confident identification of the Messiah - the temporal redemption of the Jewish people, a rebuilt Temple, peace and prosperity, the universal recognition of the God of Israel - are null and void.
2. The messianic faith of Judaism allows for the following scenario: God will finally send the true Messiah to embark upon his redemptive mission. The long-awaited redeemer will declare that all preparations for the redemption have been completed and announce without qualification that the fulfilment is absolutely imminent. He will begin the process of gathering the dispersed of Israel to the Holy Land. He will proclaim himself a prophet, point clearly to his messianic status, and declare that the only remaining task is to greet him as Messiah. And then he will die and be buried without having redemed the world. To put the matter more succinctly, the true Messiah’s redemptive mission, publicly proclaimed and vigorously pursued, will be interrupted by death and burial and then consummated through a Second Coming.
Berger is aware that the vast majority of Jews would view the above-mentioned options as totally alien to the Judaism they know. Further, as Berger reminds his readers, “the Rabbinical Council of America has declared that there is no place for such a doctrine in Judaism.” However, and this is what greatly irks Berger,
the assertion that contemporary Orthodox Jewry effectively legitimates these beliefs rests on a simple observation: a large segment - almost certainly a substantial majority - of a highly significant Orthodox movement called Lubavitch, or Chabad, hasidism affirms that the Lubavithcer Rebbe, Rabbi Manachem Mendel Schneerson, who was laid to rest in 1994 without leaving a successor, did everything subsumed under proposition 2 and will soon return to complete the redemption in his capacity as the Messiah.
Berger labels his book “an indictment, a lament, and an appeal.” In fourteen chapters he explores the historical background leading up to Schneerson being seen as the Messiah, a survey of some steps that have been taken to deal with the issue, and some sobering implications as viewed from Judaism’s perspective. Even Christians will be startled to read how some Lubavitchers refer to their rebbe. It is no wonder that Berger is concerned, for as he notes, a failure to decisively respond is nothing short of “the utter smashing of a central, millennium-old argument against the Christian mission, and effects a deformation of the Jewish religion.”
Berger’s book is not likely to find its way onto the “must read” list of most Christian leaders, but those who care to invest the time to understand these issues will be richly repaid with a fresh appreciation for the intricacies of the world of Orthodox Judaism, and as well, find fresh ways of engaging the most religous of Jews in conversation about Jesus, the one to whom believing Jews and Gentiles look for salvation and assurance of a place in God’s presence for all eternity.