We've heard the claim 'religion poisons everything' ad nauseum. Turns out that being religious has benefits even in this life. Via David Bailey at Science Meets Religion:
A 1999 study, which involved a nine-year follow-up analysis of 21,000 American adults, found that religious attendance of at least once per week resulted in seven additional years of life expectancy. What’s more, this effect mostly remained in place even after adjusting for various social factors and health behaviors [Hummer1999].
A 1997 study of 5286 weekly church attendees in Alameda County, California found that these persons were 25% less likely to die than infrequent church attendees. These results were attributed in part to better health practices, expanded social involvement, exercising more, and remaining married longer [Strawbridge1997].
In a 1998 study of 1931 elderly adults (55 years and older), weekly church attendees experienced the lowest rates of mortality in the study group, while non-attendees experienced the highest rates. This study also showed that volunteer work in addition to church attendance contributed to even longer life expectancy [Oman1998].
A 1999 study of 4000 seniors (64 years and older) found that the death hazard was 46% lower for frequent church attendees, compared with infrequent church attendees. As noted in other studies, frequent church attendees were physically healthier, had better social support, and displayed a set of healthier lifestyle behaviors [Koenig1999].
A 2004 study comparing Utah residents who are members of the Church of Jesus Christ of Latter-day Saints (LDS) with those who are not LDS confirmed, not surprisingly, that the LDS members had much lower rates of tobacco, alcohol and drug usage than the non-LDS group, since these substances are strongly discouraged by the Church. The study found that life expectancy was 77.3 years for LDS males versus 70.0 years for non-LDS males, and 82.2 years for LDS females versus 76.4 for non-LDS females. Interestingly, however, the study noted that differences in rates of tobacco use explains only about 1.5 years of the 7.3 year gap for males, and only 1.2 years of the 5.8 year gap for females. The author suggests that this additional gap may be due to better overall physical health, better social support and other lifestyle practices [Merrill2004].
In an April 2013 New York Times column, Stanford scholar Tanya M. Luhrmann summarized some of these results, and then added her own observations. In evangelical churches she has studied as an anthropologist, she found that people really do look out for one another, showing up with dinner when friends are sick, or simply talking with them when they are unhappy. They are relatively more generous, often in private contributions, when others are in need. She mentioned that when one member of an evangelical group cried at needing a $1500 dental procedure, yet had no money, her friends, many of whom were students with very limited funds, covered the cost by anonymous donations [Luhrmann2013].