Gnosticism is a collection of ancient religious ideas and systems that emerged in the early centuries of the Common Era. It emphasizes personal spiritual knowledge, or "gnosis," over orthodox teachings and institutions. Gnostics often believed that the material world was created by a lesser deity, sometimes referred to as the Demiurge, and that true divine knowledge could lead to salvation. Gnosticism encompasses various sects and texts, many of which were discovered in the Nag Hammadi library in 1945. These writings reveal diverse beliefs about the nature of God, the universe, and humanity's role within it, often contrasting sharply with mainstream Christianity and other religious traditions.