Religious beliefs and practices provide a framework of meaning to human life. They give people a sense of purpose, help them to connect with and relate to the world around them, and offer moral and spiritual guidance. In many cultures, religion also plays a critical role in social change, helping to promote economic equality and peace, to address poverty, disease, war, and inequality, and to organize resistance to injustice.

However, the complexity of religious beliefs and practices makes it challenging to define a category such as religion. Some scholars have attempted to do so by adopting a substantive definition. Others have opted for a functional definition. Both approaches have their strengths and weaknesses.

Substantive definitions often require believers to believe in unusual realities. These include a belief in a disembodied spirit or a cosmological order that exists beyond the physical realm. They may also involve a belief in an afterlife, supernatural beings, or explicit metaphysics. For this reason, substantive definitions of religion are often criticized as ideologically biased and passive images of the religious person. In contrast, a functional definition of religion is more neutral.

Emile Durkheim defined religion as whatever system of practices unites people in a moral community, whether or not these practices involve belief in unusual realities. This functional approach to the concept of religion has continued to shape sociological thinking on the topic.

A third approach to the concept of religion is to treat it as a type of societal organization. Like other societal institutions, religion evolves within and across time and culture. However, unlike most other institutions, religions typically change more slowly and are more likely to retain older features and mix together old and new ones. This kind of partial continuity, which may extend to founded and universalistic religions as well, is one of the most interesting aspects of the history of religions.

In the last forty years, there has been a reflexive turn in the study of religion. Scholars have drawn back, so to speak, and have examined the constructed nature of the objects that they have taken for granted as unproblematically “there”. This has led some to argue that the notion of religion is a social construct.

Some have gone even farther and argued that the concept of religion is an invented category, that it is not a real thing, that its modern semantic expansion went hand in hand with European colonialism, and that it is therefore inappropriate for people to treat it as something that corresponds to reality outside the sphere of modern European influence. Despite the skepticism that often surrounds these claims, they are not without merit. The problem, then, is how to proceed with the comparative study of religions when a conceptualization of what religion is has become so problematic.