The Adivasi people are 8.6% of India's population, over 100 million. These are tribal people, the indigenous people, the original peoples of India. There are many tribes, and the Indian Constitution recognises the Scheduled Tribes, though they continue to struggle to hold on to their land and culture.
My anrscestors worked directly with the Oraon tribe, as well as the Munda tribe. These two tribes are very different in language and origins, but they lived together in the jungles of Chotanagpur. Now they are scattered in various Jharkhand, Bengal, Bihar, Odisha, Chhaatisghar and as far as Assam.
About half of the Adivasi today are Christian. In 1868 when my anscestors first arrived in India there were a few thousand Christians in the region. Now the Gossner Evangelical Lutheran Church in Chotanagpur and Assam alone has over 500,000 members. There are others who are members of the CNI and Catholic church and various other Protestant and Pentecostal churches. This church that my ancestors helped establish remains predominantly Adivasi and was one of the first native churches to receive autonomy (1919).
See video above of a Oraon Christian celebration of Thanksgiving.