Maretu, from the village of Ngatangi‘ia, island of Rarotonga, was a man of power. As a boy he ate defeated enemies from his father's cannibal oven, and once angered his elders when he stole a victim's head to have for himself. In 1823, he met a Tahitian named Papeiha, who told him of an omnipotent god and, suitably impressed, himself became a preacher for the new religion. Stories about Maretu accumulated. A man who insisted on seeing Maretu's hand, scarred in an accident, was told he would die, and collapsed the next day. Villagers assisting Maretu wade across a lagoon feared the spiny creatures on the bottom and found that they moved apart to create a clear footway.

At Manihiki, where Maretu himself was preaching the new faith, he introduced the technique of igniting lime by burning coral rocks. As his memoirs record, he called “heathen” islanders around him in the night. One said to him, “I suppose the fire of the god of darkness down below is something like this,” to which Maretu replied, “tomorrow this fire will die, but the one you speak of will never die. It burns forever . . .” The heathen asked what kind of firewood it was that burned forever, to which Maretu replied, “Those who refuse to believe in Jesus are the firewood.” “And what's the fire?” “That's the anger of God . . . if all the people believe in Jesus Christ, then the fire will die.” All of the listeners decided to become Christian.