Religion is a broad concept that encompasses a wide range of practices. It is most often used to refer to a set of beliefs and behaviors such as prayer, meditation, worshipping god, fasting, and attending religious services, among other things. It is also sometimes used to describe specific types of faith such as Christianity, Islam, Hinduism, or Buddhists.
The study of religion has taken two main approaches. One is formal, in which scholars try to find a set of secondary traits that can be found across all cases. This approach is often based on the notion that there is some kind of essential meaning to religion. The formal definitions of religion are often rooted in the work of Durkheim and others (Dobbelaere and Lauwers 1973).
Another approach is substantive, in which scholars try to see what kinds of activities constitute a religion. This is a more difficult approach, and it can lead to different definitions of religion. Some, such as Frazer, define religion in terms of a belief in power greater than oneself and an attempt to propitiate these powers. Other scholars, such as Lemert and Blasi, take a more holistic view of religion and identify a set of properties that are common to all religious phenomena.
Finally, some scholars are taking a more reflexive approach to the study of religion. They are looking at how the concept of religion is a cultural construct that has been imposed on other cultures. This is a political process, and it is not surprising that the definition of religion changes over time as people try to assert their own views on what constitutes religion.