Religion is a primary source of faith for many people. People need faith and meaning and value for orienting their lives and for addressing their most profound questions and concerns. They are willing to live according to and, at times, die for their religion. Other sources of value like science, family, and work can also serve as such objects of faith but there are few others that are so intensely and comprehensively embraced by individuals and societies.
Whether we study them as such or not, the fact is that all religions play an important role in the lives of most people. To understand these religions better it is necessary to consider their structure, their disciplinary practices, and the mental states they produce in people.
There are two ways to go about this task: one is to use a social taxon approach and try to define the concept of Religion in terms of essential properties or a set of conditions that must be met by a phenomenon to qualify as a religious practice; these are called substantive definitions. This is the approach taken by Edward Tylor, for example, who defined religion in terms of belief in spiritual beings or cosmological orders. The other way is to take a functional approach and try to define the concept of religion in terms of the function that a form of life can play in one’s life, as proposed by Emile Durkheim or Paul Tillich.