Religion is a cultural system of beliefs, practices and ethics. It is a key part of most cultures and can be a source of morality and social cohesion. It also provides people with a sense of purpose and direction in life which has been linked to better mental health and lower rates of depression and suicide.

The definition of religion varies widely across cultures and over time, with some scholars opting for monothetic-set definitions (such as the one proposed by Rodney Needham) while others adopt polythetic approaches that treat the concept of religion as a complex. This approach allows for the discovery of patterns and correlations in a set of characteristics, and may lead to explanatory theories. For example, Ninian Smart’s “Anatomy of Religion” is an example of a polythetic approach.

As an anthropologist, Clifford Geertz has emphasized the importance of the symbolic dimensions of religion, including devotional practices, worship and prayer, moral conduct, and right belief. Other scholars have also focused on the role of institutions and organizations in the formation of religious beliefs, practices and behaviors.

In the United States and other western countries, many people have no religion or only a nominal one. However, some studies suggest that regular attendance at religious services can increase longevity and improve the chances of recovering from illness. These benefits are often attributed to the sense of community that religious participation creates. Some research suggests that religiosity can also encourage healthy behaviors like diet and exercise.