Religion is a group of beliefs and practices that give its followers a reason to live and a hope for the future. It addresses questions that science cannot answer—the existence of a divine creator, the meaning of life, and what happens after death. It provides a framework for human behavior and a code of ethics. Many different religions exist, but most share similar characteristics—they are based on belief in something sacred and offer some kind of hope for the future, whether it is that there will be life after death or that people will be judged by their deeds rather than their genes.
Social theorists Emile Durkheim, Max Weber, and Karl Marx are among those who founded the academic study of religion. Their ideas helped to shape a discipline that today defines religion as a social taxon, a category concept for sets of cultural practices. These theories treat religion as a family-resemblance concept and reject its substance definitions (that is, the idea that a practice must involve believing in a distinctive kind of reality).
Other researchers take a polythetic approach to religion by looking at how different practices function in society. For example, they may look at how religious communities organize themselves—such as through organizational structures like a cult, denomination, or ecclesia. These studies also seek to understand how and why religious traditions change over time. The National Council for the Social Studies has long advocated that teachers include the study of religion in their classrooms to help students become active participants in a pluralistic democracy.