This book is a history, an indictment, a lament, and an appeal, focusing on the messianic trend in Lubavitch hasidism. It demonstrates how those who affirm the dead Rebbe's messiahship have abandoned a Jewish core belief in favor of the doctrine of a second coming. It also decries the equanimity with which the standard- bearers of Orthodoxy have legitimated this development by continuing to recognize such believers as Orthodox Jews in good standing. This abandonment of the age-old Jewish resistance to a quintessentially Christian belief is a development of striking importance for the history of religions, and it is an earthquake in the history of Judaism. David Berger chronicles this development from a personal viewpoint. He describes the growing concern that impelled him to undertake an anti-messianist campaign - publications, correspondence, and the sponsorship of a Rabbinical Council of America resolution excluding this belief from authentic Judaism. He argues that a large number, almost certainly a substantial majority, of Lubavitch hasidism believe in the Rebbe's messiahship; a significant segment, including educators in the central institutions of the movement, maintain a theology that goes beyond posthumous messianism to the affirmation that the Rebbe is pure divinity. While many Jews see Lubavitch as a marginal phenomenon, its influence is in fact so remarkable that its representatives are poised to dominate Orthodox religious institutions in several major countries throughout the world. This book analyzes the boundaries of Judaism's messianic faith and its conception of God. It assesses the threat posed by Lubavitch messianists and points to the consequences, ranging from undermining a fundamental argument against the Christian mission to calling into question the kosher status of many foods and ritual objects prepared under Lubavitch supervision. Finally, it proposes a strategy to protect authentic Judaism from this assault. David Berger is Professor of History at Brooklyn College and the Graduate Center of the City University of New York. He is a Fellow of the American Academy for Jewish Research, and from 1998 to 2000 was President of the Association for Jewish Studies. He is the author of The Jewish-Christian Debate in the High Middle Ages and co-author of Judaism's Encounter with Other Cultures: Rejection or Integration'.