Religion is a category of beliefs, practices and values that people hold for themselves and that they are willing to live according to and even die for. It is the most intensive and comprehensive way of valuing that people experience.
The word “religion” comes from the Latin religio, which means a feeling of scrupulousness or a sense of obligation. The concept of religion has evolved from that original sense to a general notion of social genus that appears in all cultures and that may be understood through the same types of principles as other societal phenomena, such as the need for trust and a moral order.
Scholars have generally attempted to define religion by using either functional or substantive approaches. Functional definitions tend to be broad and inclusive, including such things as Communism, nationalism and atheism, while substantive definitions are narrower and more restrictive. Both approaches have their limitations and the main problem with defining religion is that there is such a variety of beliefs and practices globally that it will be impossible to come up with a definition that will please everyone.
There is also a growing skepticism that the word “religion” is a Western concept that doesn’t make much sense in non-Western traditions. However, that doesn’t mean that the term should be dropped. As a practical matter, it is still very useful to use the word when dealing with interfaith issues and for academic purposes. It just takes a lot of work to dive into the meaning of religion and understand what it truly is.