Nag Hammadi library in the context of "Pachomian monastery"

Sophia (Koine Greek: Σοφíα "Wisdom", Coptic: ⲧⲥⲟⲫⲓⲁ "the Sophia") is a figure, along with Knowledge (γνῶσις gnosis, Coptic: ⲧⲥⲱⲟⲩⲛ tsōwn), among many of the early Christian knowledge theologies grouped by the heresiologist Irenaeus as gnostikoi (γνωστικοί), "knowing". Gnosticism is a 17th-century term expanding the definition of Irenaeus' groups to include other syncretic faiths and the Greco-Roman mysteries.

In Gnosticism, Sophia is a feminine figure, analogous to the human soul but also simultaneously one of the feminine aspects of God. Gnostics held that she was the syzygy, or female twin, of Jesus, i.e. the Bride of Christ, and the Holy Spirit of the Trinity. She is occasionally referred to by the term Achamōth (Ἀχαμώθ, Hebrew: חכמה chokmah) and as Prunikos (Προύνικος). In the Nag Hammadi texts, Sophia is the highest aeon or anthropic emanation of the godhead.

A lost literary work (referred throughout this article just as a lost work) is a document, literary work, or piece of multimedia, produced of which no surviving copies are known to exist, meaning it can be known only through reference, or literary fragments. This term most commonly applies to works from the classical world, although it is increasingly used in relation to modern works. A work may be lost to history through the destruction of an original manuscript and all later copies.

Works—or, commonly, small fragments of works—have survived by being found by archaeologists during investigations, or accidentally by laypersons such as, for example, the finding Nag Hammadi library scrolls. Works also survived when they were reused as bookbinding materials, quoted or included in other works, or as palimpsests, where an original document is imperfectly erased so the substrate on which it was written can be reused. The discovery, in 1822, of Cicero's De re publica was one of the first major recoveries of a lost ancient text from a palimpsest. Another famous example is the discovery of the Archimedes Palimpsest, which was used to make a prayer book almost 300 years after the original work was written. A work may be recovered in a library, as a lost or mislabeled codex, or as a part of another book or codex.

The Apocryphon of John, also called the Secret Book of John or the Secret Revelation of John, is a 2nd-century Sethian Gnostic Christian pseudepigraphical text attributed to John the Apostle. It is one of the texts addressed by Irenaeus in his Christian polemic Against Heresies, placing its composition before 180 AD. It tells of the appearance of Jesus and the imparting of secret knowledge (gnosis) to his disciple John. The author describes it as having occurred after Jesus had "gone back to the place from which he came".

The Gospel of Thomas (also known as the Coptic Gospel of Thomas) is a non-canonical sayings gospel. It was discovered near Nag Hammadi, Egypt, in 1945 among a group of books known as the Nag Hammadi library. Scholars speculate the works were buried in response to a letter from Bishop Athanasius declaring a strict canon of Christian scripture. Most scholars place the composition during the second century, while some have proposed dates as late as 250 AD and others have traced its signs of origins back to 60 AD. Some scholars have seen it as evidence of the existence of a "Q source" that might have been similar in its form as a collection of sayings of Jesus, without any accounts of his deeds or his life and death, referred to as a sayings gospel, though most conclude that Thomas depends on or harmonizes the Synoptics.

The Coptic-language text, the second of seven contained in what scholars have designated as Nag Hammadi Codex II, comprises 114 sayings attributed to Jesus. Almost two-thirds of these sayings resemble those found in the canonical gospels and its editio princeps counts more than 80% of parallels. Experts speculate that the gospel's other sayings were added from Gnostic tradition. Its place of origin may have been Syria, where Thomasine traditions were strong. Other scholars have suggested an Alexandrian origin.

The Asclepius, also known as the Perfect Discourse (from the Greek Logos teleios), is a religio-philosophical Hermetic treatise. The original Greek text, which was likely written in Alexandria between 100 CE and 300 CE, is largely lost and only a few fragments remain. However, the full text is extant in an early Latin translation, and fragments from a Coptic translation have also been found among the documents discovered in Nag Hammadi.