Coptic refers to the language and culture of Christians in Egypt from approximately the second century A.D. until today. Coptic is the final stage in the development of the ancient Egyptian language; Coptic is written in the Greek alphabet and incorporates many Greek words. Before its use as a popular language gradually died out after the Moslem conquest of Egypt in the seventh century, Coptic was the language of a rich but little-known literary and liturgical corpus of which the Nag Hammadi manuscripts are one of the best-known representatives.

Gnostic (pronounced “nostik”) refers to the beliefs and practices of a variety of religious groups that relied on secret knowledge revealed only to a select few. (Gnosis is the Greek word for this non-empirical insight.) Gnostic teachers frequently combined spiritual wisdom from several sources and traditions, including Christian, Jewish, Greco-Roman, Egyptian, or Iranian thought, into syncretistic systems reserved for their own devotees. In these systems, physical and historical ways of understanding reality and human experience were rejected in favor of spiritual and mystical modes of understanding. Some scholars reserve the term “Gnostic” for the developed systems of heretical Christian teachers of the second century A.D. such as Basilides and Valentinus. Others use the term “gnosis” (note the lower case “g”) as a general term. It is important to remember that “Gnostic” does not always mean “heretical,” since the definition of orthodoxy was an ongoing process that was not complete when Gnostic ideas and practices flourished.