Ātareta Kāwana Rōpiha Mere Rikiriki, born probably in 1855 or 1856 and known as Mere Rikiriki, was the daughter of Kāwana Rōpiha (also known as Kāwana Hūnia) of Ngāti Tauira, and Mere Rikiriki of Ngāti Te Rangitepaia. She had links with Rangitāne and Ngāti Apa and was raised near Parewanui, Rangitīkei. She was a descendant of Maata, a noted medium and healer during the 1840s, and was the only woman prophet in a nineteenth century tradition of spiritual succession that embraced Tāwhiao Te Wherowhero, Te Kooti, Tohu Kākahi, Te Whiti-o-Rongomai, Hipa Te Maihāroa, and T. W. Rātana. In her adult years she spent time at Parihaka with Te Whiti and Tohu Kākahi. On 27 July 1910 her standing was expressed when she baptised herself seven times at the Rangitīkei River in a special ritual calling upon the Holy Spirit. This date is still commemorated annually at Parewanui.
Sometime in the early 1900s Mere Rikiriki inaugurated Te Hāhi o te Wairua Tapu (the Church of the Holy Spirit), involving adherents of the Ringatū faith and Māori members of other churches. At a prayer meeting at Parewanui at Christmas 1911 she said the spirit of prophecy had entered her, and she was recognised as a prophet. Although Mere had some of the mana of a tohunga, the church was based on Christian scriptures and stressed the mediating role of the Holy Spirit and the unity of Māori under God and the Treaty of Waitangi.
Mere Rikiriki was small, had a light moko and wore plaited hair. She practised faith healing and the use of Māori herbal remedies. An enlightened and knowledgeable speaker, she was well versed in the Scriptures. In spite of her critics she continued to draw large crowds, and many people demonstrated their trust and confidence in her faith and healing powers.
In 1912 Mere Rikiriki foretold the coming of a new prophet. This reinforced the earlier prophecy of Te Kooti that a leader would emerge in the west who would restore the mana of the Māori. Her followers initially thought she was referring to either Rangi Māwhete or Panau Tamatai, but she later confirmed that the future prophet was her close kinsman, Tahupōtiki Wiremu Rātana, then working as a farmhand on family land. She had earlier named two of his sons Ārepa and Ōmeka (Alpha and Omega), although she refused to touch or baptise them, claiming their spiritual power was too great.
Mere Rikiriki was instrumental in laying the foundations for Rātana's teachings. With her counsel he was strengthened, and eventually she passed her healing gifts to him; he often consulted her. A series of signs and revelations, coupled with Mere Rikiriki's teachings, led him to develop his Christian-based beliefs and his stress on the importance of the Treaty of Waitangi. After 1918 Rātana became well known beyond his tribal area as a prophet, healer and leader. Mere Rikiriki herself signed the Rātana covenant in 1926.
Mere Rikiriki also inspired the Māramatanga movement. In comparison to Rātana's religious mission of putting aside the past and eliminating old tapu, including the powers of the tohunga, Māramatanga blended Māori custom and Catholic beliefs. The movement's founder, Hōri Ēnoka, who was known as Māreikura, was supported and guided by her. Mere Rikiriki's influence and mana is demonstrated by King Tāwhiao's presentation to her of the flag 'E Te Iwi Kia Ora'; this was a prized taonga (treasure) with significant markings known as Te Paki o Matariki, including two mere crossed in the foreground. She also acted as a mentor to Rangi Māwhete, who became Rātana's principal contact with the New Zealand Labour Party and was made a member of the Legislative Council in 1936.
Mere Rikiriki's legacy is visible in the Rātana movement and the Māramatanga, which are still closely interwoven. The strength of her influence can be found among Māori communities throughout New Zealand. She died at Parewanui on 13 March 1926. Mere and her husband, Īnia Te Rangi, had no children, but the lines are maintained by the descendants of her brothers Tāmati and Tīemi.