Let us begin by granting that various qualifications must be assumed for each mention of a Gnostic tenet. This is because of the variety of doctrine amongst the various Gnostic schools such as the Syrian or Semitic, Hellenistic or Alexandrian, dualistic and antinomian-and phases such as the Basilides, Valentinus, Marcion, Docetae and Demiurge.
In the second century Irenaeus, the Bishop of Lyones in 180 AD, wrote a work entitled Adversus Haereses - Against Heresies. Chapter XXXI:1-3 of this text is subtitled Doctrines of the Cainites and states:
As a metaphor let us mention that Roman Catholicism is a particular culture that is centered around the temporal, human, leadership of the Pope. It is a Pope-Culture, if you will. Yet, there are competing cultures that claim equal status and authority, one such faith is Pop-Culture. Both, Pope-Culture and Pop-Culture claim infallibility when speaking out officially on matters of faith and morals (or lack thereof).