Religion is a collection of beliefs, practices, and values that people use to make sense of their world. It often involves a god or spirit as well as rules for how to behave and ideas about what happens after death. Religion can bring people together and provide a basis for moral behavior, but it can also cause problems such as discrimination and conflict. The study of religion helps us understand these problems.

It is difficult to come up with a definition of what counts as a religion. Several attempts have been made to find some defining property, such as the numinous experience, the contrast between sacred and profane, or belief in one or more gods. But all of these efforts have failed to provide a clear definition because the rich variety of religious phenomena makes it hard to find an element that distinguishes them all.

More recently, scholars have adopted a different approach. This is sometimes called a functional definition of religion and it focuses on the role that a phenomenon can play in a person’s life. For example, Emile Durkheim defined religion as whatever system of practices unite a group of people into a moral community, whether or not those systems involve belief in unusual realities.

These kinds of functional definitions help us see more clearly what characteristics all religions have in common. The more of these features a particular phenomena has the more likely it is to be regarded as a religion. But, like a family tree, not all phenomena will show every characteristic; some may be described as magic, sorcery, or cults instead of as full-blown religions.