What is religion? That's a hard question to answer. And the harder you try, the more difficult it becomes.
Is "religion" simply defined as the way we think about God? If so, Buddhism is not a religion, because many Buddhists don't believe in God. Nor do some Hindus and Unitarians and Jews. Add to those a lot of liberal Catholics who don't believe in God but won't admit it, plus a whole bunch of liberal Protestants whose definition of "God" is certainly not traditional.
Does "religion" mean simply living an ethical life? If so, then many good, nice, ethical atheists are religious.
Perhaps "religion" refers to an organized institution. But that can't be, because there are many religions (such as Quaker and Hindu sects) that resist any effort to organize. And many more religions that are not organized even though they think they are!
So in order to talk about "religion," it first becomes necessary to define the term.
One definition that seems to cut across many philosophical boundaries was developed by the sociologist Joachim Wach, who lived from 1898 to 1955. His "Three Forms of Religious Expression" comes close to capturing the elusive concept of religion.
Theoretical
This word refers to the fact that religions teach something. They have a "theoretical" component.
Religions teach by means of myths, doctrines, traditions, and customs. Sometimes it drives religious leaders crazy to hear from congregants, over and over again, "We've always done it this way!" But customs, stemming from myths and stories, cemented by doctrine, and interpreted by longstanding traditions, teach young people in ways they never quite outgrow. How many atheists, for instance, are still afraid of going to the hell in which they no longer believe? It's because the theoretical component of their childhood religion was so strong they cannot ever fully outgrow it.
Whenever we study a new religion, we ask about its teachings. That's what religions do. They teach something. They teach how the world was made, how humans came to be, what will happen in the future, how to live in the present. They pass on values and ethics by teaching children the social standards of their religious community. That's what Sunday school, catechism classes, and confirmation classes are for. That's why religious institutions of higher learning were formed.
Religions are all about teaching.
Practical
Religions also have developed ways of worshiping. "Practical" refers to what people in various religions actually do. Jews go to synagogues or observe family religious celebrations at home. Catholics go to Mass. Protestants attend church services. Muslims fulfill the Five Pillars.
Religious communities are known for their traditions. What makes us uncomfortable when we go to a worship service different from our own tradition is that we don't always know what is expected of us. We don't know the rituals. We don't know the customs. We are afraid of bumping into a "sacred cow."
Religions have a traditional practice, a "practical" component.
Sociological
Religions also attract a community. They have a sociological component. In New England, every town has a little white community church on the town common. In European cities, it's the cathedral that dominates the skyline. In Midwestern America, the "little brown church in the vale" is being replaced by the ultra-modern educational complex with an extensive bus ministry. California has its Crystal Cathedral. Jerusalem its Dome of the Rock. Mecca its Kaaba.
What kind of a community forms around a religion? The answer provides its sociological component.
So we might define "religion" in this way, using the words of Robert S. Ellwood, co-author of the textbook Many Peoples, Many Faiths:
While the essence of religion may be beyond words, the religious experience … expresses itself in human life in three ways. These three forms of religious expression (are) theoretical, practical and sociological.
Sources: Ellwood, Robert S., and Barbara A. McGraw. Many Peoples, Many Faiths. 6th ed. Upper Saddle River, NJ: Prentice Hall, 1999.
