Gnosticism used a number of religious texts that are preserved, in part or whole, in ancient manuscripts or are lost but mentioned critically in Patristic writings.
Prior to the discovery at Nag Hammadi, only the following texts were available to students of Gnosticism. Reconstructions were attempted from the records of the heresiologists, but these were necessarily coloured by the motivation behind the source accounts.
Works preserved by the Church:
Acts of Thomas (Especially The Hymn of the Pearl and The Hymn of the Robe of Glory)
The Acts of John (Especially The Hymn of Jesus)
The Bruce Codex (purchased in 1769 by James Bruce):
The Gnosis of the Invisible God or The Books of Jeu
The Untitled Apocalypse or The Gnosis of the Light
The Askew Codex (British Museum, bought in 1784):
Pistis Sophia: Books of the Savior
The Berlin Codex or The Akhmim Codex (found in Akhmim, Egypt; bought in 1896 by Carl Reinhardt):
The Gospel of Mary
Apocryphon of John
an epitome of the Acts of Peter
The Wisdom of Jesus Christ
Unknown origin:
The Secret Gospel of Mark
The Hermetica
Codex I (also known as The Jung Codex):
The Prayer of the Apostle Paul
The Apocryphon of James (also known as the Secret Book of James)
The Gospel of Truth
The Treatise on the Resurrection
The Tripartite Tractate
Codex II:
The Apocryphon of John
The Gospel of Thomas a sayings gospel
The Gospel of Philip
The Hypostasis of the Archons
On the Origin of the World
The Exegesis on the Soul
The Book of Thomas the Contender
Codex III:
The Apocryphon of John
The Gospel of the Egyptians
Eugnostos the Blessed
The Sophia of Jesus Christ
The Dialogue of the Savior
Codex IV:
The Apocryphon of John
The Gospel of the Egyptians
Codex V:
Eugnostos the Blessed
The Apocalypse of Paul
The First Apocalypse of James
The Second Apocalypse of James
The Apocalypse of Adam
Codex VI:
The Acts of Peter and the Twelve Apostles (includes The Hymn of the Pearl)
The Thunder, Perfect Mind
Authoritative Teaching
The Concept of Our Great Power
Republic by Plato - The original is not gnostic, but the Nag Hammadi library version is heavily modified with then-current gnostic concepts.
The Discourse on the Eighth and Ninth - a Hermetic treatise
The Prayer of Thanksgiving (with a hand-written note) - a Hermetic prayer
Asclepius 21-29 - another Hermetic treatise
Codex VII:
The Paraphrase of Shem
The Second Treatise of the Great Seth
Gnostic Apocalypse of Peter
The Teachings of Silvanus
The Three Steles of Seth
Codex VIII:
Zostrianos
The Letter of Peter to Philip
Codex IX:
Melchizedek
The Thought of Norea
The Testimony of truth
Codex X:
Marsanes
Codex XI:
The Interpretation of Knowledge
A Valentinian Exposition, On the Anointing, On Baptism (A and B) and On the Eucharist (A and B)
Allogenes
Hypsiphrone
Codex XII
The Sentences of Sextus
The Gospel of Truth
Fragments
Codex XIII:
Trimorphic Protennoia
On the Origin of the World
The so-called "Codex XIII" is not a codex, but rather the text of Trimorphic Protennoia, written on "eight leaves removed from a thirteenth book in late antiquity and tucked inside the front cover of the sixth." (Robinson, NHLE, p. 10) Only a few lines from the beginning of Origin of the World are discernible on the bottom of the eighth leaf.
The Hymn of Jesus
Acts of Peter
Apocalypse of Adam
Coptic Apocalypse of Peter
Dialogue of the Saviour
Odes of Solomon
Gospel of Judas
Unknown Berlin Gospel or Gospel of the Saviour
These texts are mentioned or partially quoted in the writings of the Church Fathers.
Gospel of Basilides mentioned by Origen, Jerome, Ambrose, Philip of Side, and Bede.
Basilides' Exegetica mentioned in Hippolytus of Rome (Refutatio Omnium Haeresium VII, i-xv and X, x) and Clement of Alexandria (Stromata IV, xii and IV, xxiv-xxvi)
Epiphanes' On Righteousness, mentioned in Clement of Alexandria (Str. III, ii).
Heracleon, Fragments from his Commentary on the Gospel of John, mentioned in Origen (Commentary on the Gospel of John)
Naassene Fragment mentioned in Hippolytus (Ref. 5.7.2-9).
Ophite Diagrams mentioned in Celsus and Origen
Ptolemy's Commentary on the Gospel of John Prologue, mentioned in Irenaeus.
Ptolemy's Letter to Flora, mentioned in Epiphanius.
Theodotus: Excerpta Ex Theodoto mentioned in Clement of Alexandria.
Askew Codex contains Pistis Sophia and some other unknown texts.
Berlin Codex, 5th century, contains a fragmentary Gospel of Mary, out of nineteen pages, pages 1–6 and 11-14 are missing entirely, the Apocryphon of John, The Sophia of Jesus Christ, and an epitome of the Act of Peter.
Bruce Codex contains the first and second Books of Jeu and three fragments - an untitled text, an untitled hymn, and the text "On the Passage of the Soul Through the Archons of the Midst".
Codex Tchacos, 4th century, contains the Gospel of Judas, the First Apocalypse of James, the Letter of Peter to Philip, and a fragment of Allogenes.
Nag Hammadi library contains a large number of texts (for a complete list see the listing)
Three Oxyrhynchus papyri contain portions of the Gospel of Thomas:
Oxyrhyncus 1: this is half a leaf of papyrus which contains fragments of logion 26 through 33.
Oxyrhyncus 654: this contains fragments of the beginning through logion 7, logion 24 and logion 36 on the flip side of a papyrus containing surveying data.
Oxyrhyncus 655: this contains fragments of logion 36 through logion 39 and is actually 8 fragments named a through h, whereof f and h have since been lost.
