There are two senses of religion. In the anthropological sense, religion is what a person uses to organize their interpretation of the universe. Every human has one, even the nonbelievers subscribe to something like naturalism or physicalism in their worldview.
In the common usage, a religion is an organized set of beliefs, traditions, etc., that one subscribes to. Not everyone has one.
In the common usage, a religion is an organized set of beliefs, traditions, etc., that one subscribes to. Not everyone has one.