Religion is the set of beliefs and practices that tell people what is morally right, what one should avoid, and how to live. Religion can also refer to a specific religious tradition, such as Christianity or Islam, or it can be more broadly used to describe a group of believers or worshippers. Many of these traditions include prayers, sacraments, rites of passage, holy days, and the use of icons, artwork, and dress codes to express spirituality. The idea of a supreme being, or god or gods, can be found in all religions. Some people believe in only one god, while others accept several. Still others do not believe in any gods at all.
The concept of religion is a controversial one. Some scholars have pushed for more rigorous definitions of the term, especially in the light of the problems that have been caused by religion. For example, some argue that there is no such thing as religion because there is always a difference between what a person believes and what they practice. This view rejects the classical notion that every instance of a category will share a defining property with other instances. It is sometimes referred to as a “monothetic” definition of the term, as opposed to a more modern “polythetic” approach (see below).
Others have argued that despite the fact that a person may not practice a given religion, they can be considered religious by virtue of their belief in a certain kind of reality. This is sometimes referred to as a “functional” definition of the term. One sees this approach in Emile Durkheim, who defines religion as whatever system of practices unite a number of people into a single moral community (whether or not those practices involve belief in any unusual realities).
A third approach is to say that a religion is not a “thing” but simply a way of life. This approach often takes on a form of cultural relativism, as some cultures define religion in different ways from other cultures.
There are also some scientists who have proposed theories about why people think in terms of religion. For example, psychologists have argued that people tend to be religious in response to psychological needs, such as fear of death and the desire for social connection. They also point to the influence of parenting and culture on the development of religious beliefs. Finally, some neuroscientists have argued that the human brain contains circuitry that can give rise to religious experiences.
These and other ideas about what is and is not a religion have led to some very contested definitions of the term. For example, some people have criticized the use of the word to describe areas of study that most would not consider to be religious in nature, such as cosmology and ecology. Others have argued that because studies of these subjects provide benefits to humans, they should be included in any definition of religion. These arguments are not directly related to the controversy over what constitutes a religion, but they reflect the way in which the definition of religion is entangled with assumptions about what is important to human beings.