The Process, or in full, The Process Church of the Final Judgment, commonly known by non-members as the Process Church, was a religious group that flourished in the 1960s and 1970s, founded by the English couple Mary Ann and Robert de Grimston (originally Mary Ann MacLean and Robert Moor). Originally headquartered in London, it had developed as a splinter group from Scientology, so that they were declared "suppressive persons" by L. Ron Hubbard in December 1965. In 1966, members of the group underwent a social implosion and moved to Xtul on Mexico's Yucatan peninsula, where they developed "processean" theology (which differs from, and is unrelated to process theology). They later established a base of operations in the United States in New Orleans.
They were often viewed as Satanic on the grounds that they worshiped both Christ and Satan. Their belief was that Satan would become reconciled to Christ, and they would come together at the end of the world to judge humanity, Christ to judge and Satan to execute judgment. Vincent Bugliosi, the prosecutor of the Charles Manson family trial, comments in his book Helter Skelter that Manson may have borrowed philosophically from the Process Church, and that representatives of the Church visited him in jail after his arrest. According to one of those representatives, the purpose of the visit was to question Manson about whether he had ever had any contact with Church members or ever received any literature about the Church. The group published an article about Manson and the jail visit in the The Process magazine's special "Death" edition.