Traditionally, Lucifer is a name that in English generally refers to the Devil or Satan before being cast from Heaven, although this is not the original meaning of the term. In Latin, from which the English word is derived, Lucifer (as a noun) means “light-bearer” (from the words lucem ferre). It was the name given to the dawn appearance of the planet Venus, which heralds daylight. For this meaning, English generally uses the names “Morning Star” or “Day Star”, and rarely “Lucifer”.
An ancient myth of the fall of angels, associated with the Morning Star, was transferred to the Devil, as seen in the Life of Adam and Eve and the Second Book of Enoch, which the Jewish Encyclopedia attributes to the first pre-Christian century. In these writings, Satan-Sataniel (sometimes identified with Samael) is described as having been one of the archangels. Because he contrived “to make his throne higher than the clouds over the earth and resemble ‘My power’ on high”, Satan-Sataniel was hurled down, with his hosts of angels, and since then, he has been flying in the air continually above the abyss.
The Early Christian writers Tertullian (“Contra Marcionem,” v. 11, 17), Origen (Homilies on Ezekiel 13), and others identify Lucifer with the Devil, who also is represented as being “cast down from heaven” (Revelation 12:7–10; cf. Luke 10:18).
Today, some contemporary exorcists and theologians, such as Father José Antonio Fortea and Father Amorth, assert that Lucifer and the Devil are different beings.
In the New Testament the “adversary” has many names, but “Lucifer” is not among them. He is called “Satan” (Matt. 4:10; Mark 1:13, 4:15; Luke 10:18), “devil” (Matt. 4:1), “adversary” (1. Peter 5:8, ἀντίδικος; 1. Tim. 5:14, ἀντικείμενος), “enemy” (Matt. 13:39), “accuser” (Rev. 12:10), “old serpent” (Rev. 20:2), “great dragon” (Rev. 12:9), Beelzebub (Matt. 10:25, 12:24), and Belial (comp. Samael). In Luke 10:18, John 12:31 and Rev. 12:9 the fall of Satan is mentioned. The devil is regarded as the author of all evil (Luke 10:19; Acts 5:3; 2. Cor. 11:3; Ephes. 2:2), who beguiled Eve (2. Cor. 11:3; Rev. 12:9). Because of Satan, death came into this world, being ever the tempter (1. Cor. 7:5; 1. Thess. 3:5; 1. Peter 5:8), even as he tempted Jesus (Matt. 4). The Christian demonology and belief in the devil dominated subsequent periods. However, though the New Testament includes the conception that Satan fell from heaven “as lightning” (Luke 10:18; Rev. 12:7–10), it nowhere applies the name Lucifer to him.
The Jewish Encyclopedia states that in the apocalyptic literature, the conception of fallen angels is widespread. Throughout antiquity, stars were commonly regarded as living celestial beings (Job 38:7). Indications of belief in fallen angels, behind which probably lies the symbolizing of shooting stars, an astronomical phenomenon, are found in Isaiah 14:12.