Religion is one of the most complex and contested phenomena in human history. It is a huge and diverse field, covering such topics as belief in god or gods, prayer, holy scriptures, sacred texts, miracles, sacrifice, reincarnation, the afterlife, and rituals. It is sometimes a difficult term to define, since it can be used in different ways by different people. Some use it to refer to all systems of beliefs, while others restrict it to the observable practices that create community and give meaning to life. Still others may limit the concept to those that include a belief in an afterlife or supernatural beings. It can also be defined functionally, such as the beliefs and practices that help generate social cohesion or provide orientation in life.
There are many theories on the origin of religion. Some anthropologists (scientists who study human cultures and societies) believe that religion evolved as a response to either a biological or cultural need. In the case of biology, it may have been a result of the emergence of consciousness and the realization that humans will eventually die. It could be seen as a way to alleviate this fear by giving hope of a better place after death or of an immortal soul.
The other theory is that religious beliefs and practices are a natural part of the human experience. It is said that humans have a need to explore their own nature, their world, and the relationships they have with each other and the universe. In this view, religions are an important means to do so. Religions offer people confidence in their future and a sense of belonging to a larger family, whether it is a nation, a church, or a group of believers. Religions also provide a focus for goals that are too big or too dangerous to achieve in this life, such as peace, enlightenment, emptiness (see shamanism), or Buddha-nature.
Some scholars have argued that to define religion in terms of mental states and beliefs reflects a Protestant bias and that it is more useful to look at the visible social structures that produce these beliefs and practices. This has led to the development of a more functional or functionalist definition of religion, which emphasizes its ability to provide social cohesion and direction in life. This has become the dominant approach in the Western world. But in other regions, scholars have used the more traditional, substantive or phenomenological definition of religion. In fact, there are probably as many definitions of religion as there are religions themselves. Each may have its own strengths and weaknesses, but none is complete in itself. They all have some common features, however.