Lucifer

In modern and late Medieval Christian thought, Lucifer (Hebrew: הילל, Lucifer, "light-bearer" shining one, morning star, v. to praise, glorify, laud, commend) is a fallen angel commonly associated with Satan, the embodiment of evil and enemy of God. Lucifer is generally considered, based on the influence of Christian literature and legend, to have been a prominent archangel in heaven (although some contexts say he was a cherub or a seraph), prior to having been motivated by pride to rebel against God. When the rebellion failed, Lucifer was cast out of heaven, along with a third of the heavenly host, and came to reside on the world.

Lucifer was originally a Latin word meaning "light-bearer" (from lux, "light", and ferre, "to bear, bring"), a Roman astrological term for the "Morning Star", the planet Venus.

"I will put enmity between you and the woman, and between your offspring and her offspring; he shall bruise your head, and you shall bruise his heel." Genesis 3:15 ESV

The word Lucifer was the direct translation of the Greek eosphorus ("dawn-bearer"; cf. Greek phosphorus, "light-bearer") used by Jerome in the Vulgate. In that passage, Isaiah 14:12, it referred to one of the popular honorific titles of a Babylonian king; however, later interpretations of the text, and the influence of embellishments in works such as Dante's The Divine Comedy and John Milton's Paradise Lost, led to the common idea in Christian mythology and folklore that Lucifer was a poetic appellation of Satan.

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Satan

Satan (שָׂטָן Standard Hebrew Satan, from the proper name Σατανάς Sátanas, Arabic شيطان Shaitan: both words mean "Adversary; accuser") is a Judeo-Christian term which is, together with the Islamic term Shaitan, traditionally applied to an angel, demon, or minor god in many religions. The idea of this ultimate agent of evil was most likely introduced by the Iranian (Persian) prophet Zoroaster as the Prince of Darkness, whose ideas for the first time introduced Demons and Angels to humanity, and would later influence Judeo-Christian beliefs. Although, Zoroaster’s beliefs concentrated on the duality and the struggle of the ultimate good and the ultimate evil, it would be the Jews, having adapted these beliefs, who would later portray Satan as the inferior enemy of God, and not the all power evil fighting the all powerful creator of man, which is what Zoroasterians believed. Satan plays various roles in the Hebrew Bible, the Apocrypha and the New Testament. In the Hebrew Bible, Satan is an angel that God uses to test man for various reasons usually dealing with his level of piety (i.e. the test in the Book of Job).

In the Apocrypha and New Testament, Satan is portrayed as an evil, rebellious demon who is the enemy of God and mankind. However, in both Jewish and Christian theology Satan is no longer understood as a true equal to God.

Since both religions are intentionally monotheistic, Satan is seen, rather, as a creature created by God-originally good, but now fallen of his own choosing. This prevents a true dualism in both religions. Good is the original status of all things made by God. Corruption comes later at the hand of created moral agents (consider Augustine of Hippo's notion of privation here).  Thus Satan is always under God's providential control and at times even his unwilling agent.

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