Religion is a broad category of human belief systems and practices. It includes all of the world’s major religions, such as Christianity, Judaism, Islam, and Hinduism, as well as beliefs that are new, uncommon, not part of a formal church or sect, only subscribed to by a few people, or seem illogical or unreasonable to others. Religion also includes religious observances and activities, such as worship, prayer, and study of sacred texts. Unlike many social institutions, which change rapidly and often are separable from cultures, religions develop more slowly and often blend older features with new ones.
Most attempts to analyze the concept of religion use a “monothetic” approach, holding that every instance of a religious phenomenon will share some defining property. But the last several decades have seen a shift to a more functional definition of religion. Emile Durkheim, for example, defines religion as whatever system of practices unite a group into a moral community (whether or not those practices involve belief in any unusual realities).
This perspective stresses that religions are more than just beliefs and rituals; they serve multiple purposes in society. They promote and reinforce social stability and cohesion, help people deal with death and loss, provide a basis for moral beliefs and behaviors, and even affect health. Unfortunately, some religions are a source of social conflict, as evidenced by the fact that both individuals and entire nations have been willing to persecute and kill each other because of their religious beliefs or affiliations.