Religion is the human system of beliefs and practices that are based on the idea that there is a supreme being, or gods, or spirits. It includes all the many ways in which people express those beliefs, from gestures and art to dietary laws, cosmological theories, and social institutions, including holy places, sacred texts, and religious dress. It also encompasses all the many rituals and other acts associated with them.

While it is possible to be a good, moral person without religion, for most humans, religions are the source and source of the means to attain the most important goals they can imagine. Some of those goals are proximate, and can be achieved within this life (a wiser, more fruitful, more charitable, more successful way of living), or the next one, or within the process of rebirth; others are ultimate, and have to do with the eventual condition of this or any other human person or of the cosmos itself.

For most religions, there is a set of rules and norms that are expected to be adhered to by all members. These often include the prohibition against murder, and the obligation to forgive others. Religious systems also often include prayers, and a belief in reincarnation or other forms of immortality. Various studies have shown that regular attendance at church, synagogue or temple is associated with higher levels of happiness and wellbeing. These findings should be treated with caution, however, as they are not based on a causal link and may simply reflect the fact that religious activity provides people with access to different methods of coping with stress.