A one-sentence description of Gnosticism: a religion that differentiates the evil god of this world (who is identified with the god of the Old Testament) from a higher more abstract God revealed by Jesus Christ, a religion that regards this world as the creation of a series of evil archons/powers who wish to keep the human soul trapped in an evil physical body, a religion that preaches a hidden wisdom or knowledge only to a select group as necessary for salvation or escape from this world.
The term “gnostic” derives from “gnosis,” which means “knowledge” in Greek. The Gnostics believed that they were privy to a secret knowledge about the divine, hence the name. (Huxley coined “agnosticism” on the basis that all knowledge must be based on reason. We cannot rationally claim to have access to knowledge that is beyond the powers of the intellect.)
There are numerous references to the Gnostics in second century proto-orthodox literature. Most of what we know about them is from the polemic thrown at them by the early Church Fathers. They are alluded to in the Bible in the pastorals (spurious Paulines of 1 Timothy, 2 Timothy, and Titus), for example 1 Tm 1:4 and 1 Tm 6:20, and possibly the entirety of Jude. Ignatius of Antioch writes against them as well as Docetism, a doctrine closely related to Gnosticism that stated that Christ was pure spirit and had only a phantom body. Second Clement is a document aimed at refuting early second century Gnosticism. Marcion was the most famous of the Gnostics, and he established a “canon” of the Pauline epistles (minus the pastorals) and a “mutilated” Luke (presumably considered so because it lacked proof-texts such as Lk 22:43-44). Justin Martyr mentioned him c. 150 CE, and Irenaeus and Tertullian wrote against him extensively in the late second century (in Against Heresy and Against Marcion, respectively).
Besides Marcion, other important Gnostics were Basilides and Valentinus. Some Gnostic documents are the Gospel of Truth, the Letter to Rheginus, Treatise on the Three Natures, Apocalypse of Adam, the Gospel of Matthias, Gospel of Philip, Acts of Peter, and Acts of Thomas. Although the Gnostics were prolific writers, most of their works have been burnt or lost in favor of proto-orthodox writings (and known only through patristic references).
Some scholars have theorized that Gnosticism has its roots in pre-Christian religions, instead of being merely an offshoot of Christianity.
The following are writings by Gnostics of the second century according to some scholars, although some others dispute this classification for writings such as the Gospel of Thomas.
- Gnostic: The Gospel of Thomas
- Gnostic: The Secret Book of James
- Gnostic: Basilides
- Gnostic: Naassene Fragment
- Gnostic: Gospel of Mary
- Gnostic: Dialogue of the Savior
- Gnostic: Gospel of the Savior
- Gnostic: Marcion
- Gnostic: Epiphanes
- Gnostic: Ophite Diagrams
- Gnostic: Ptolemy
- Gnostic: Gospel of Truth
- Gnostic: Excerpts of Theodotus
- Gnostic: Heracleon
- Gnostic: Acts of Peter
- Gnostic: Acts of Thomas
All of the above documents and more are presented on the Early Christian Writings web site.
Here are some books about Gnostics and Gnosticism.
- Gnosis : The Nature and History of Gnosticism by Kurt Rudolph
- The Gnostic Gospels by Elaine Pagels
- The Gnostic Paul by Elaine Pagels
- Rethinking “Gnosticism” by Michael Allen Williams
- The Elements of Gnosticism by Stuart Holroyd
- Gnostic Truth and Christian Heresy : A Study in the History of Gnosticism by Alastair H. B. Logan
Here are some web pages about Gnostics and Gnosticism.