Following a foreword and an executive summary, the introduction explains that faith-based organizations (FBO’s) have a history of contributing monetary funds to social service programs that assist over 70 million Americans annually. Many studies have linked involvement in religious practices (organic religion) to reductions in many types of deleterious health outcomes. Relatively little is known, however, about the effectiveness of FBO’s. In the first section, the authors present the findings from 669 studies about the effects of organic religion and 97 studies concerning the diverse interventions of religious groups, FBO’s, and congregations (intentional religion). The studies on organic religion overwhelmingly indicate that greater involvement in religious practices is associated with reduced hypertension, longevity, reduced depression, lower levels of alcohol and drug consumption, less engagement in risky sexual behavior, reduced risk of suicide, reduced delinquency, and reduced criminal activity. In the next section, 669 studies are reviewed concerning the relationship between religion and well-being. Taken together, the findings indicate that higher levels of religious involvement provide protective factors that generally reduce deleterious social outcomes. Greater involvement in religious practices conveys the sense of well-being, purpose, meaning, and educational attainment. Thus, religious involvement is associated with promoting prosocial behaviors and enhancing positive outcomes. The following section assesses 97 studies concerning the effectiveness of FBO’s (intentional religion). A critical analysis of these studies indicates that studies on intentional religion are much less common than studies on organic religion, they rely too heavily on the case study method while eschewing quantitative methodologies, and they have definitional problems in measuring the “faith” in FBO’s. Despite these limitations, the evidence suggests that FBO’s, congregations, and other religious groups are effective at delivering various services. The authors call for funding from both private and public sources to more thoroughly study the contribution of FBO’s in providing social services. The literature review also contains a section describing the methodology followed for locating research, which mainly involved computer database searches with key terms. Tables, appendix, notes