The impact of organized religions like Hinduism, Christianity and Islam on tribal communities has long been recognized. Tribes in India have been influenced by certain traditions of Hindus living near them. Hindu texts like Puranas and epics have references to interaction between Hindus and tribes .For instance there are more than 300 references to tribes in the epic Mahabharata. Lord Rama lived in Chitrakut forests in the company of tribes. Sabari who offered fruits to Lord Rama hailed from Bhil tribe.
Some tribes are assimilated at different levels in the caste structure of Hindus. The Tharu and Khasa tribes of the Himalayan terrain have distinctive tribal customs but have been accepted as Kshatriyas. The practice of wearing sacred thread has been recorded in the Tharu tribe. The Khasas have modeled their ways of life as defined among Rajputs living in adjoining plains.
In Central India the Cheros, the Khanuars and the Purahiyans have been influenced by the Kshatriya caste. The Bauris of West Bengal claim to have come into the folds of Brahminism since they wear the sacred thread accept Vaishnavaism and go on pilgrimages for worship. Hindu Gods and Goddesses are worshiped in some Oraon villages and many have given up eating beef. Bhakti cult of Hinduism has influenced the Mundas and their traditional Bonga cult has lost its influence on some people. A new caste Manjhis in which the Hindu way of life is defined has emerged in the Munda tribe.
In Central India sanskritization among certain section of tribes has been attributed to the Bhagat movement. The movement instituted in 1914 among Oraons of Chotanagpur stood for purging beliefs in ghosts and spirits and in making people repose faith in Mahadeo.Bhagats today constitute sanskritised groups in which Brahminical way of life is defined.
After India came under British rule, Christian missionaries living among some tribes contributed to culture change. The first impact of conversion to Christian faith was among Khasis of Assam in 1850.The conversions begun first at individual and family level. In course of time the pace of conversion increased.
The major concentration of Christians is located in Northeast states. In Central India the highest number of Christians is among the Kharia tribe. Christianity has been responsible in changing the outlook of tribes in the fields of education, festivals, social and economic life. There is the view that impact of Christianity led to the disintegration of traditional and cultural values and also in the creation of caste like groups among tribes. At the same time many sections of different tribes have come under a single religious leadership of the Church. Among those tribes who have undergone religious change, indigenous tribal festivals, youth dormitories, traditional dances and values have considerably declined.
Some of the tribes face cultural change due to acculturation, regionalism, assimilation and so forth. Acculturation is responsible for the change in ways of life of some tribes like Raj Gonds and Tharus.When some cultural traits of a powerful group are imposed on a weak cultural group; there is the danger of the weak group losing its cultural identity. In such a context the weak group may rise against to regain its cultural identity. The solidarity movements in Rajasthan and Jharkhand evidence such contra-acculturation process.