The Cainites were an early Gnostic sect who taught that Cain, Judas, and other ungodly persons were actually spiritual seekers who resisted the evil Creator.
Others declare that Cain derived his existence from the Power above. They acknowledge that Esau, Korah, the Sodomites, and all such persons are related to themselves. . . . They maintain that Judas the traitor was thoroughly acquainted with these things. . . . They produce a fictitious history of this kind, which they call the Gospel of Judas. Irenaeus (c. 180, E/W), 1.358.
A viper of the Cainite heresy . . . has carried away a great number of persons with her most venomous doctrine. She makes it her first goal to destroy baptism. Tertullian (c. 199, W), 3.669; extended discussion: 1.358