Inri Cristo was raised by two Roman Catholic farmers of German ancestry, Wilhelm and Magdalena Theiss. Inri had a humble childhood and studied for about three years at the Adolfo Konder School. He quit studying in order to help his mother, whom he calls "the woman who raised him", with domestic supplies, since his father was retired due to a work accident. Since childhood, Inri has claimed to obey a "powerful voice" that speaks inside his head. Obedient to this voice, he left home at thirteen to live independently of his family. In adolescence he worked as a greengrocer, baker, delivery boy, peddler and waiter. Eventually, Inri severed all ties to Christianity, becoming an atheist, until he received what he calls the "revelation of his identity".
In 1969, at the age of 21, Inri began his public life as a self-professed prophet and astrologer, introducing himself as "Iuri de Nostradamus". In 1971, he began speaking on television, with TV Morena, and this opportunity introduced him to a wider audience. In 1976, claiming to blaze the trail of spiritual transcendence, Inri became vegetarian. In 1977 he lived for some time in Copacabana Palace hotel, in Rio de Janeiro, a part of high society. In 1978, he left Brazil on a tour through Latin America, speaking on radio. In 1979, obeying the same powerful voice that he claims to have heard since childhood, he underwent a fast in Santiago, Chile. On this occasion, he says, the voice said in a rasping voice, "I am your Father", and revealed itself to be the "God of Abraham, of Isaac, and of Jacob". This voice, he says, said that he was the same Christ crucifiedtwo thousandyears ago under Pontius Pilate. It also said that the second letter of his name would henceforth be upside down, making his name "Inri", the acronym for Iesus Nazarenus Rex Iudaeorum. Inri launched a pilgrimage over many countries, dressed in a white tunic and sandals, announcing that his mission would be accomplished in the dawn of a New Age of peace. Inri wandered over 27 countries spreading his message. In 1980, Inri was expelled from the United States, from Venezuela and from England. France sheltered him for nine months and even announced in Antenne 2: "Le Christ est revenu sur la terre". On this occasion, Inri was invited to speak in the Grande École Polytechnique de Paris. Back in Brazil, on February 28, 1982 Inri performed what he calls a "libertarian act". He broke into the cathedral in Belém in Pará state. Accused of profanation and vandalism by the clergy, he was sent to jail for fifteen days. On this occasion, he established a new mystical order, SOUST, which he calls "the formalization of the promised Kingdom of God on Earth". On April 20, 1982, Inri Cristo officially established SOUST in Curitiba, where he remained for 24 years in a "provisional" headquarters. He has been detained by police more than forty times, owing to his statements and unusual way of dressing. He is often invited to give lectures in many colleges and universities throughout Brazil, and is usually well received by students.