Religion is a complex, multifaceted concept. Attempts to define it are not only of interest in sociology, history, anthropology, and psychology, but also to many ordinary people who are puzzled about why religion should exist, how it should be practiced, whether it contributes to social problems such as inequality and conflict, or promotes psychological well being and positive social change.
Some definitions of religion emphasize a belief in certain unusual realities, such as God or angels. Others, based on the work of Emile Durkheim, stress the function that religion serves in society. This functional approach resists a passive image of humans as passive recipients of charisma or legitimacy from outside forces, and allows for a greater range of beliefs and practices to be considered religion.
This type of definition enables scholars to look for patterns in religion, such as the co-occurrence of certain characteristics. Alternatively, some scholars use a polythetic approach that defines religion as a taxon for sets of social practices. This allows for a wide variety of religious-practice groups to be included in the same category, although it is not easy to determine how many characteristics a group must have in order to be classified as a religion.
This approach is useful for examining the nature of religion, and for understanding how people create and sustain it. It can also help us to understand why some people make such extraordinary sacrifices for their religion, including renouncing their jobs and families, in order to follow a religious path they believe will lead them closer to God or to achieve peace with the universe.