Religion is a huge and highly diverse set of human activities, beliefs, and behaviors. It encompasses a broad range of practices, including belief, ritual, morality, and mythology. It also covers a wide array of worldviews, including those related to the cosmos and to the afterlife. It is also a powerful force in the world, affecting politics, economics, and culture, and it often serves to unify people of similar beliefs and values. However, the concept of religion is controversial. Many scholars argue that it is a social construction. Others believe that it has a necessary role in society, and that it should be protected from criticism and ridicule. The controversy is partly caused by the difficulty of distinguishing what constitutes a religion from other forms of human activity.
There are various ways of approaching the definition of religion, and different approaches are usually used in combination. Some scholars prefer a functional definition, which tends to focus on the effects of religious practices on individuals and society. Other scholars use a more substantive definition, which focuses on the characteristics of religious phenomena. Still other scholars use a polythetic definition, which attempts to group religious phenomena according to a number of criteria, including secondary characteristics, such as the presence of certain symbols or rituals.
Those who prefer a functional definition often feel that to think of religion in terms of mental states such as beliefs is to ignore the fact that religion has real, tangible effects on the world around us. They argue that religion brings benefits to individuals, families, societies, and the nations, such as improved health, learning, self-control, emotional stability, and economic well-being. In addition, it reduces the incidence of some social pathologies, such as out-of-wedlock births, violence and murder, addictions, health problems, and prejudices.
Others, however, find that a functional definition is too restrictive. Edward Burnett Tylor, for example, argued that to limit religion to the belief in spiritual beings would exclude Judaism, Christianity, Islam, Hinduism, Buddhism, and Confucianism. Furthermore, he believed that narrow definitions are based on ethnocentric assumptions and that it is important to understand the universality of religion.
Other scholars reject a functional definition and prefer a substantive one. They believe that to consider religion as an invented category is to ignore the fact that it grew out of European colonialism, and that its modern semantic expansion went hand in hand with European ideas about the world and its place in it. They argue that to define religion in terms of a belief in a supernatural being is to ignore the fact that it is rooted in a need to make life seem rational and just. Furthermore, they argue that to define religion in terms of observable structures is to miss the point of its origin and development as a tool of power. They suggest that a better way to address this issue is to develop a theory of religion as a set of interlocking systems of beliefs and practices.