Second Temple Judaism exerted a profound and shaping influence upon early Christianity. This book documents this influence by exploring the ways in which the Christian praxis of Christ-devotion in the first two centuries of the Common Era can be understood as a manifestation of Jewish monotheism. The volume approaches this phenomenon along four distinctive lines of inquiry: (1) re-examining (and problematising) the theological force of monotheism during the Second Temple period; (2) retracing the historical steps of Christianity's adaptation, mutation, and/or redefinition of Jewish monotheism; (3) exploring and debating the influence of non-Jewish traditions on this process; and (4) mapping how Christianity's unique appropriation of Jewish monotheism helps explain the intriguing relationships among emerging Christian, Jewish, and gnostic communities. Eighteen chapters, each from an expert in the study of early Judaism and Christianity, comprise the volume. The chapters collectively demonstrate how the creation of new mythic narratives, the revelatory power of mystical experiences, and the sociology of community formation capitalised on Jewish mediator traditions to initiate the praxis of Christ-devotion.