What was occurring in Jude’s time was an early form of Gnosticism, often called “Incipient Gnosticism,” i.e., not fully developed.
Gnostic asked the question, “How could infinite pure spirit have anything to do with an evil material body?” There were two solutions to this dilemma:
Jesus was not really human—he only appeared to be. This was called Docetism which came from the Greek word dekeo which is defined as “to seem.” This made Jesus a ghost, an illusion; he seemed to be a man but had no real existence.
Jesus’ spirit did not inhabit his body until his baptism and his spirit left before his death. This was called Cerinthianism, from its leader, Cerinthus. This made Jesus a Dr. Jekyll-Mr. Hyde; one did not know when Jesus was human or when he was divine. The dualism of good and evil may be the background for what Jude says in v. 4a, i.e., …who changed the grace of our God into a license for immorality and deny Jesus Christ our only Sovereign and Lord.
