Challenging the Orientalist exoticisation of mantras and their restriction to 'Eastern religions', Joseph L. Kimmel traces the understanding, practice, and purposes of mantras across a variety of historical and cultural contexts, from early Christianity to the present day. This comparative approach reveals the richness and versatility of this ancient tradition, offering an illuminating account of its significance and function. Beginning with the origins of Indic mantras in ancient Vedic traditions and their reinterpretation along Tantric Hindu and Buddhist lines, this book illuminates how mantric-like speech has also characterised Christian practices in understudied ways, from the early Christians' invocations of Jesus to medieval and contemporary iterations of the Orthodox 'Jesus-prayer'. This volume provides insight into the 'manifestation' mantras of present-day self-help practices, tracing their rise and analysing how their purpose and use converges and departs from Buddhism, Hinduism and Christianity. What emerges is a compelling case for mantras' enduring relevance, widespread appeal and ongoing significance.