Religions are groups of people who have organized ways of believing and behaving, in order to create a sense of meaning in their lives. Religious people believe in some supernatural force or other, often a god or goddess who watches over humankind and who will punish the wicked and reward the good. They also believe in a destiny which extends beyond their own existence, often a journey to heaven or hell. In addition, most religions develop codes of recognition and behavior which can organize hierarchies. Religions are usually very powerful and influential, influencing people’s values and attitudes.

The term religion is a very difficult one to define, and attempts to do so have tended toward either functional or substantive definitions. Functional definitions are those which look at the ways in which a particular religion serves a specific function in its followers’ lives. This approach has been taken by Durkheim, and by Paul Tillich who viewed religion as whatever dominant concern in a person’s life helps to organize the individual’s values (although it need not involve belief in any unusual realities).

Substantive definitions are those which take into account the ideas held by the religious people themselves. This approach has been used by O’Dea and others. A problem with substantive definitions is that they seem to impose a certain image of humans as passive social actors which has been resistant to scientific progress. This has also led to debates about whether it is appropriate for a concept to have fuzzy edges and to allow for the intangible, or whether scientific development should begin with sharply defined, clear cases and move to broad categories.

Both approaches have advantages and disadvantages. For example, functional definitions can be criticized for not being able to distinguish between what is actually religious and what might be useful or interesting. Also, they tend to treat religion as something that exists in its own right, independent of the values and attitudes of its adherents, whereas it is better to view it as a way of helping humans cope with limitations which are both real and acknowledged.

Ultimately, it is impossible to settle the question of how to define religion. There will always be some degree of controversy, even among scholars. This is because the nature of religion is so complex and varied, that there are many things which could be called a religion. But this does not stop the ongoing research into religion, as the study of its effects on society and on the lives of its followers is a vital part of our modern world. It is worth remembering that the study of religion was a major factor in the Renaissance, which brought Europeans into contact with many new religions. This helped to prepare the way for a more modern, comparative treatment of religion. The need for this was highlighted by such events as the Inquisition and the Salem witch trials, and the growing trend for more or less systematic compilations of mythological material.