Ratana was of the Ngati Apa and Ngā Wairiki tribes — his subtribes were Nga Ariki, Ngāti Hikapirau, Ngāti Rangiwaho, Ngāti Kiriwheke and Ngati Kauae —and on his mother's side he was of Ngā Rauru Kiitahi, His mother belonging to the Rangitaawhi Hapū. He Married Te Urumanao Ngāpaki Baker, who had whakapapa links to the Ngāti Ruanui, and possibly Te Āti Awa also.
Ratana began his spiritual mission during the 1918 influenza epidemic. Ratana claimed that while standing the veranda of his home at 2pm, on 8 November 1918, three days before the end of the First World War, he saw a small cloud coming in from the sea toward his house. When the cloud 'broke open' he was overwhelmed by a presence and he rushed into the house declaring 'Peace be unto you all, for I am the Holy Spirit that speaks to you all. Straighten yourselves. Repent'. He was told the Holy Spirit was looking for a people through whom [[God] could be truly known and accepted. The Māori people had not forgotten Jehovah and so they had been chosen to become an example to the world if only they would turn from their dependence on tohungaism (particularly the manipulative forms of witchcraft) and Maori gods. Ratana was told to unite the Māori and turn them to Ihoa o nga Mano (Jehovah of the Multitudes). Ratana continued his study of the Bible and began one of the most powerful faith healing ministries in New Zealand history. He came known as "Mangai" (a mouthpiece of God) gained a large following among Māori.
From 1922 onwards the Ratana movement became increasingly occupied with politics. The movement campaigned for ratification of the Treaty of Waitangi as a "cure-all" for Māori problems and collected 30,000 signatures on a petition calling for this. In 1928 Ratana proclaimed that Ratana candidates would win the four Māori seats in the New Zealand Parliament, likening them to the four parts of his body, or the Four Quarters, as the seats became known. Eruera Tirikatene arranged a meeting with Michael J. Savage in Parliament on 4 February 1936 at which an alliance with the Labour Party was agreed. Savage's predecessor Harry Holland had been reluctant, because of the animosity between Ratana and the Māori King Movement, especially Princess Te Puea. By 1943, the seats had been won, although Ratana died in 1939. The alliance with Labour lasted for over 40 years.
The Ratana Church remains one of the largest churches in Māoridom, and the political alliance between Ratana and the Labour Party continued as a strong tie between the Māori people and the Labour party until 2008 when the Maori political party formed an alliance with the National Party, seeming to bring an end to the Labour party's apparent monopoly on Māoridom.
- Ratana the Prophet, Keith Newman, Penguin 2008