Paul Bloom discusses in Slate whether religious people are, in fact, happier:
Maybe, then, religious people are nicer because they believe that they are never alone. If so, you would expect to find the positive influence of religion outside the laboratory. And, indeed, there is evidence within the United States for a correlation between religion and what might broadly be called "niceness." In Gross National Happiness, Arthur Brooks notes that atheists are less charitable than their God-fearing counterparts: They donate less blood, for example, and are less likely to offer change to homeless people on the street. Since giving to charity makes one happy, Brooks speculates that this could be one reason why atheists are so miserable. In a 2004 study, twice as many religious people say that they are very happy with their lives, while the secular are twice as likely to say that they feel like failures.