This article summarizes research prior to 2010 and more recent research on religion, spirituality, and health, including some of the latest work being done by research teams at Columbia University, Harvard University, Duke University, and other academic medical centers. First, terms such as religion, humanism, and spirituality are defined. Second, based on his research team's previous systematic review of quantitative studies published in the peer-reviewed literature prior to 2010, the author discusses the findings from that research on the effects of religion and spirituality (R/S) on (1) mental health-well-being, purpose in life, hope, optimism, self-esteem, depression, anxiety, suicide, and substance abuse; (2) health behaviors-exercise, diet, cigarette smoking, and risky sexual activity; and (3) physical health-coronary artery disease, cancer, and all-cause mortality. Third, the author examines the latest research on the prevalence of spiritual needs among individuals with serious or terminal medical illnesses, the consequences of ignoring those needs, and the results of clinical trials that have examined the effects of spiritual assessments by physicians. Finally, the author reviews the research currently being conducted at Duke University on the efficacy of religious cognitive-behavioral therapies and on the effects of religious involvement on telomere length in stressed caregivers. Resources are provided that will assist seasoned researchers and clinicians who might be interested in doing research in this novel and expanding area of whole-person medicine.