Religion is a cultural system of beliefs, values and ethics. Generally, religion deals with what might be called the supernatural or spiritual, about forces and powers beyond the control of humans. Most religions offer some sort of hope for a better future, a higher purpose to life and a way to cope with tragedy and loss. This hope is what distinguishes religion from philosophy or purely ethical systems.
There are many theories about what religion is and how it operates. Some approaches attempt to define religion in a rigorous way, with a minimum set of properties that must be present in a religion for it to qualify as one. These are known as monothetic definitions. Edward Tylor proposed such a definition in 1871 when he defined religion as belief in spirit beings. Another approach attempts to determine whether a belief is religious by evaluating its impact on the person who holds it. This is known as a functional definition and was proposed by Paul Tillich.
A third approach considers the way a religion is transmitted from generation to generation and whether it has a cultural legacy. Clifford Geertz offered such a definition in 1973. Other theories include a cognitive or evolutionary explanation, the idea that religion originated out of human curiosity about the big questions of life and death or out of fear of uncontrollable forces that could be used against humanity.
Psychologists, scientists who study the human mind, suggest that religion meets emotional and psychological needs in humans, such as a need to cope with death or a need for meaning to life. Neuroscientists, scientists who study the brain and nervous system, think there is actually some neurological basis for the feelings and experiences of religiosity.
It seems that most people agree that some sort of religion is important to most humans and that it affects their lives in positive ways, even though they may disagree about what the nature of that religion might be. For example, there are studies that show that people who have a religious faith tend to be more generous than those who do not and that they are more likely to volunteer in charity organizations. There are also studies that show that religion has a negative effect on people’s health, such as increased likelihood of smoking and drinking and poorer dental hygiene.
While substantive and functional definitions are the most popular in the academic study of religion, there is a growing interest in polythetic or heuristic approaches to understanding what a religion is. These are based on the observation that many phenomena appear to share some of the same characteristics and so can be grouped together in categories based on their shared features. A common analogy is the way a computer program might sort bacteria according to their similar properties. It might then be possible to discover patterns that could lead to explanatory theories. The same is possible for the study of religion.