Functional theories explaining the evolution of primitive religion were propounded by Malinowski and Radcliffe Brown. Malinowski gives the example of Trobriand Islanders whose religion is intimately associated with various emotional states of tension. The magical and religious practices of the islanders surround fishing expeditions.
They fear of disasters overtaking them while on fishing expeditions. Various situations in the lives of people give rise to tensions based on anger, hate, and greed and so on. These states leading to tension continue for long, frustrations sets in. Religion helps to get rid of stress and strain, paving way for attaining mental poise and stability.
Radcliffe considers that the function of religion is not to purge emotional stresses and strains from mind but to instill a sense of dependence of the mind on religion. The survival of group is more important than that of an individual. So the individual must be prepared to make certain sacrifices. The reason is that individual survival is not possible without survival of society.
Durkheim's theory on religion states that when people gather for festivals and to celebrate social events mutual discussions between members give birth to religious notions. Religion is divided into beliefs, theology and rites. While beliefs are static, rites are dynamic. Belief in Gods and deities is put into practice by the performance of rites. Profane beliefs fall into the realm of magic and sorcery and do not belong to religion.