Religion is a complex human phenomenon that encompasses a wide range of practices, ideas, and experiences. The social genus that is religion has been around for thousands of years and continues to be a significant part of the lives of people worldwide. It can be defined functionally or substantively, in a variety of ways. Traditionally, sociological approaches to religion have focused on the functions it serves for society rather than its beliefs or practices. Emile Durkheim’s work in particular stressed that the function of religion was to unite people into a moral community, and this view still shapes many sociological perspectives on religion.

A social-science definition of religion includes any unified system of beliefs and practices that people hold to be sacred, absolute, spiritual, divine, or worthy of especial reverence. This could include beliefs in disembodied spirits and cosmological orders, as well as more mystical and abstract concerns such as a higher purpose, moral code, or spiritual salvation. Depending on the cultural context, these religious attitudes and activities may be oriented toward a higher power or a more personal god.

Many social-science perspectives on religion stress the negative aspects of religion. For example, religion can reinforce and perpetuate inequality and lead to social conflict; history shows that people are ready to persecute and kill each other over their religious differences. Other views of religion focus on the positive effects it can have on society, including helping the poor, motivating people to work for social change, and fostering physical and psychological well-being.