Religion is an influential force in today's society. Over 4 billion worldwide identify themselves with a religious group (Bedell, 1997). In the USA alone, recent polls report that 93% believe in God, 30–42% of adults (72 million) attend religious services weekly and 85% report that religion is at least fairly important in their own lives (DDB Needham Worldwide, 2000; Gallup Poll, 2001). Religion is not only an influential force but a growing force as well. In the late twentieth century came the rise of religious fundamentalism (Sherket & Ellison, 1999), the awakening of new religious movements and the expansion of other older movements such as Mormonism and Pentecostalism (Chaves, 1994). Religious beliefs about political issues and the family also continue to influence the cultural milieu. Since religion is deeply interwoven in social life, could not religion also influence health?

Research on the religion–health relationship has not only arisen from recognizing religion's continuing influence on private and public life, but also from the changing nature of medical institutions. The impersonal nature of medical treatment, burgeoning healthcare costs and the realization of science's limitations through medical mistakes have moved medical professionals and researchers to consider and examine other avenues for health promotion and treatment (Koenig et al., 2001).

Religion and medicine were virtually one and the same entity before the fourteenth century, but the divide between them grew after the 1500s, resulting after the Enlightenment in the clash between the two disciplines seen today (Koenig et al., 2001).