Many Christians believe the Devil was once a beautiful angel named Lucifer who defied God and fell from grace. This assumption that he is a fallen angel is often based the book of Isaiah in the Bible which says, “How art thou fallen from heaven, O Lucifer, son of the morning!

Lucifer is one of various figures in folklore associated with the planet Venus. The entity's name was subsequently absorbed into Christianity as a name for the devil. Modern scholarship generally translates the term in the relevant Bible passage (Isaiah 14:12), where the Greek Septuagint reads ὁ ἑωσφόρος ὁ πρωὶ, as "morning star" or "shining one" rather than as a proper noun, Lucifer, as found in the Latin Vulgate.

As a name for the Devil in Christian theology, the more common meaning in English, "Lucifer" is the rendering of the Hebrew word הֵילֵל, hêlēl, (pronunciation: hay-lale) in Isaiah given in the King James Version of the Bible. The translators of this version took the word from the Latin Vulgate, which translated הֵילֵל by the Latin word lucifer (uncapitalized), meaning "the morning star", "the planet Venus", or, as an adjective, "light-bringing".

As a name for the planet in its morning aspect, "Lucifer" (Light-Bringer) is a proper noun and is capitalized in English. In Greco-Roman civilization, it was often personified and considered a god and in some versions considered a son of Aurora (the Dawn). A similar name used by the Roman poet Catullus for the planet in its evening aspect is "Noctifer" (Night-Bringer).

Lucifer is the Latin name for the planet Venus in its morning appearances. It corresponds to the Greek names Φωσφόρος, "light-bringer", and Ἑωσφόρος, "dawn-bringer".

^ Cicero wrote: Stella Veneris, quae Φωσφόρος Graece, Latine dicitur Lucifer, *** antegreditur solem, *** subsequitur autem Hesperos. ("The star of Venus, called Φωσφόρος in Greek and Lucifer in Latin when it precedes, Hesperos when it follows the sun".

^ Pliny the Elder: Sidus appellatum Veneris […] ante matutinum exoriens Luciferi nomen accipit […] contra ab occasu refulgens nuncupatur Vesper. ("The star called Venus […] when it rises in the morning is given the name Lucifer […] but when it shines at sunset it is called Vesper".

In modern popular culture, 666 has become one of the most widely recognized symbols for the Antichrist or, alternatively, the devil.

He can open and close magical portals to Earth from Hell and back again. He can use this power to either summon or banish demons, as he does with Etrigan. He is clairvoyant, possessing a heightened perception or knowledge of time, even to the extent of being able to know the future.

According to one version of the story, Laius, king of Thebes, was warned by an oracle that his son would slay him. Accordingly, when his wife, Jocasta (Iocaste; in Homer, Epicaste), bore a son, he had the baby exposed (a form of infanticide) on Cithaeron. (Tradition has it that his name, which means “Swollen-Foot,” was a result of his feet having been pinned together, but modern scholars are skeptical of that etymology.) A shepherd took pity on the infant, who was adopted by King Polybus of Corinth and his wife and was brought up as their son. In early manhood Oedipus visited Delphi and upon learning that he was fated to kill his father and marry his mother, he resolved never to return to Corinth.