Religion is a category that can be defined in many different ways. Traditionally, the word has been understood to refer to belief in a distinctive kind of reality. In the twentieth century, however, one sees a shift toward a definition that drops this substantive element and defines religion in terms of a distinctive role that a form of life can play in people’s lives—that is, a functional definition.
This definition of religion is useful for several reasons. First, it clarifies the fact that all religious phenomena share some features. This makes it possible to compare and contrast religious beliefs and practices, even though they may differ in their cosmologies, ethical systems, and mythologies. Second, it allows us to examine religion as an element of life, not simply a set of beliefs or a system of morality. It also provides an important distinction between the religious and nonreligious, recognizing that not all belief in a deity is a religion.
A number of features characterize a religion: the tradition and maintenance of the belief system; the use of myth and symbol; the concept of salvation; the idea of sacred spaces and objects; the existence of a sacred book or writings; the practice of worship; the notion that the world has a special meaning and purpose; the code of ethics; the notion that certain kinds of behavior are inappropriate; and the idea of a leader or founder who gains almost godlike status. Most of these features are common to the various religions and distinguish them from philosophical or purely ethical systems.
All of these elements are part of the religion of Christianity, for example. They are not, however, present in all religions or even all cultures. One could argue that these features are necessary for a religion to exist. But it is also possible that they are not—that the religious phenomenon exists, but that it is not a religion by these definitions.
The etymology of the term “religion” is not clear, but it is likely to have roots in the Latin relegere, meaning “to take care of.” The earliest scholarly definitions were substantive: the religion of the ancient Greeks was called
It is possible to identify some similarities among the various religions and also to recognize some differences. For example, most religions have a belief in a creator or supreme being that is regarded as an all-powerful and loving protector of human beings. This belief in a deity engenders faith, which is a prerequisite for religion. This in turn engenders hope, the belief that Divine providence can lead to the attainment of a heavenly goal. This goal, as conceived by the religion, is a source of spiritual enlightenment that can sustain and enrich human life, and this hope, as experienced in religious worship, can bring joy. But religion can also do harm, and it is difficult to justify the exploitation of a religion by its adherents.