Religion is a broad term used to describe unified systems of beliefs and practices that give their followers something sacred in which to believe, a concept of salvation, and a code of behavior that is a moral compass for life. It also addresses a range of questions about forces and powers that are larger than humans, and religions may deal with them in highly varying ways. They can be large-scale and tightly organized, with clear hierarchies of the Pope, cardinals, bishops, priests, male and female religious orders and laity, running in parallel to spiritual hierarchies of saints, angels, gurus, or Gods, or they may be loosely structured.
In addition to addressing questions about the supernatural and the spiritual, they deal with the past and the future. For example, reincarnation is common, as are rituals designed to visit the past in order to relive and address wrongdoing (as well as the future, where it is possible to see the outcome of one’s actions). Time may be cyclical or linear, and some religions have an afterlife.
Some philosophers who would not normally be considered ‘philosophers of religion’ have worked on these matters, including A.N. Whitehead (1861-1947), Bertrand Russell (1872-1970), Martin Heidegger (1905-1976), and Jean-Paul Sartre (1905-1980). More recently, Sandra Menssen and Thomas Sullivan have pointed out that there is considerable work by continental philosophers on these issues that is often overlooked in histories of philosophy of religion. They argue that it is important to take this’reflexive turn’ seriously, so that the categories and concepts we use to sort social kinds can be analyzed for their construction and their political dimensions.