Micah Hoffman (played by Paul Lieber) was a counterculture icon who took part in a bombing incident during the 1960s. He then set out to destroy the church by creating a new persona of Jesus Christ. In the process of learning about Christ, he claimed to have actually become Christ. He then produced masterfully forged documents that he presented as heretical stories of Christ to Cardinal Augustine O'Fallon.
O'Fallon purchased the documents with the intent to destroy them to protect the faithful from documents he believed to be authentic. Mulder and Scully became involved in the bizarre events occurring around Hoffman and O'Fallon after Hoffman detonated a bomb in O'Fallon's church. Hoffman said he realized the error of his ways and tried to destroy the documents he himself had created. The case was never fully resolved because Hoffman was murdered by O'Fallon, who then committed suicide. (TXF: "Hollywood A.D.")
Hoffman is an obvious reference to real life counterculture figure and radical Abbie Hoffman, who was the "first Yippie", as Mulder refers to Micah as in the episode, in real life as he co-founded the Youth International Party or Yippies.