Religion is the cultural system people use to cope with life’s big questions, especially those about what happens after death. It usually involves belief in a god or gods and the performance of rituals and other activities that give meaning to life. It may also include texts regarded as sacred and attitudes toward the natural world. It is a complex concept that has undergone considerable change over the centuries, and many different theories have been developed. It is a subject that provokes strong emotions in believers, and there are often conflicts between people who belong to different religious groups.

The most common approach to religion is to define it as a group of beliefs and practices that claim to teach the truth, are held by a significant number of people, and have a coherent set of ethical rules. It is sometimes called the substantial definition of religion. This is the approach taken by Emile Durkheim, who said that a religion exists whenever there is a group of practices that unite a large number of people into one moral community, whether or not these practices involve belief in any unusual realities. This definition has become a staple of sociological thinking and it is widely used in discussions of religiosity, though some scholars have taken a more functional view of the concept.

Unlike the substantive and polythetic approaches, the functional approach does not impose any minimum amount of belief or practice that must be present in order to qualify as a religion. Instead, it defines what a religion is by the kinds of functions that a form of religion performs for its members. These functions might include social cohesion, identity formation, value commitment, and power.

The functional view of religion is not without its critics. Some scholars suggest that it is a kind of “reductionism” that fails to recognize the important role that religion plays in human life, and that this functional definition obscures the fact that religions are not just “belief systems” but also have a physical culture, habits, and social structures. Others have suggested adding a fourth C to the model, for community, to better reflect the importance of the material dimensions of religion.

Whatever the definition, there is no doubt that religion has a significant impact on the lives of most people. It can bring them together, but it can also divide them, particularly when there is hostility or violence based on religious differences. It can help them cope with stress, and give them a sense of purpose that enhances psychological wellbeing. It also appears to improve a wide variety of personal and societal outcomes, including health, learning, economic well-being, self-control, empathy, and moral judgments.

There is even evidence that it reduces the incidence of some social pathologies, such as out-of-wedlock births and crime. It is important to understand the complexity of the phenomenon and how it influences societies in order to develop informed policies and make good psychotherapy and education.