For many people, Religion is a core element of their life. In fact, according to the latest Pew Research Center report on U.S. Religious Landscape, about three-quarters of Americans say their religion is very important to them. Yet what does it really mean to be religious? And how does that vary from one person to the next?

Historically, most attempts to define the concept of religion have been “monothetic,” meaning that they hold to the classical view that every phenomenon that accurately falls under a given category will share certain defining properties. Monothetic definitions tend to focus on beliefs and behaviors, arguing that they are the most essential components of Religion. In contrast, more recently there has tended to be an increase in the number of social scientists who use “polythetic” approaches. They use a master list of “religion-making” features, arguing that, as long as a phenomenon has a sufficient number of them, it must be considered Religion. The problem with this approach, though, is that the list is likely to consist of prototypes (i.e., more or less the things that first come to mind when someone hears the word Religion).

Substantive definitions of religion are sometimes criticized for holding to an ideological image of humans as passive social actors. If, for example, Religion is defined substantively in terms of a belief in a distinctive kind of reality, then it becomes possible to interpret it as merely an add-on to the world’s natural order—that is, a sort of supernatural extension of the material world. Alternatively, if Religion is defined functionally in terms of the ability to provide a sense of orientation to human existence, then it becomes possible to construe it as an active process that takes on a directive role in society.

Anthropologists often suggest that religion may have evolved out of early human attempts to control uncontrollable parts of the environment, such as weather, pregnancy and birth, or success in hunting. Manipulative efforts to do so—such as magic and rituals—often were accompanied by supplication to a higher power, gods or goddesses.

In the past, most religions have been monotheistic, with believers worshipping only a single god. Some of the earliest historical religions, however, were polytheistic. Examples include ancient Egyptian and Mesopotamian religions, along with Hinduism, Judaism, Buddhism, Confucianism and others.

Many people, both adherents and non-adherents of Religion, take it for granted that their Faith is the one true religion. This is why, for example, many Christians believe that their Faith is the best one in the world, while Muslims, Jews and Hindus argue that theirs is, too.

Other scholars argue that the issue of which Religion is the best or right one in the world can only be answered if we look at the different Faiths as culturally and historically constructed objects. That way, we might learn something new about why some Religions appear to have more followers than others. In the process, we might also learn something about the nature of Religion as a social construct, and how this is reflected in its popularity.