Religion is the set of philosophies, practices and ethics that people follow in their quest to please God. It is also a concept that has been defined as a category of social formations, though the notion of a social kind so labeled predates the development of a language for it and may have existed in human societies before language became widespread enough to enable naming.
The most common definitions of religion, like those of Edward Tylor and Paul Tillich, define it as belief in a particular kind of reality. These are called “substantive” definitions because they determine whether something is a religion based on the presence of some particular feature.
A number of scholars argue that substantive definitions of religion fail to give us a good handle on the phenomenon because they focus too much on hidden mental states. They call for a shift in the focus of definitions from beliefs to the structures that produce them, a strategy they call a functional approach.
Some scholars who take a functional approach go further, asserting that religious beliefs are irrelevant to the study of religion. They suggest that what makes a particular practice a religion is the way it deals with ultimate concerns that people have about their lives and death, in addition to other matters that science cannot explore. For example, a religion may provide an explanation of why people die and a path to the next life. An alternative theory, popularized by anthropologists who study human culture and human origins, is that people created spirituality because it served a biological or cultural need.