The inner experience of spiritual and religious feelings is an integral part of the everyday lives of many individuals. For over 100 years the role of religion as a deterrent to suicidal behavior has been studied in various disciplines. We attempt to systematize the existing literature investigating the relationship between religion/spirituality and suicide in this paper. After an overview of the attitudes of the dominant religions (e.g., Catholicism, Islam, and Buddhism) toward suicide, the three main theories that have speculated regarding the link between religion and suicide are presented: “integration theory” (Durkheim, 1897/1997), “religious commitment theory” (Stack, 1983a; Stark, 1983), and “network theory” (Pescosolido & Georgianna, 1989). Subsequent to this theoretical introduction, we report on studies on religion/spirituality keeping the suicidal path as a reference: from suicidal ideation to nonlethal suicidal behavior to lethal suicidal behavior. Studies presenting indications of religious beliefs as a possible risk factor for suicidal behavior are also presented. The last section reviews possible intervention strategies for suicidal patients and suicide survivors. Indications for future research, such as more studies on nonreligious forms of spirituality and the use of qualitative methodology to achieve a better and deeper understanding of the spiritual dimension of suicidal behavior and treatment, are offered.