Satan (or the Devil) appears in both the Old and New Testaments of the Bible. Surprisingly, however, most of what people believe about Satan doesn't come from the Bible. For instance, the common image of Satan as a forked-tailed, horned demon with a goat's body from the waist down derives more from the Greek god Pan than anything biblical. What, then, does the Bible say about Satan?
The Hebrew name Satan (pronounced SA-tan) actually means "adversary," and most often in the Hebrew Bible it is prefaced by the direct object, meaning "the adversary" rather than a distinct personal name. Satan's role grows more developed both in scope and magnitude through time, and, thus, in the earlier writings of the Hebrew Bible, Satan exists not so much as an individual character but as an adversarial position occupied by both humans and angels.
For example, the word satan is used for a human potential adversary in the Philistine army (1 Samuel 29:4), and two kings God raise to be Solomon's adversaries (1 Kings 11:14, 23). An angel of the LORD is called satan when he blocks the path of Balaam (Numbers 22:22, 32). Satan becomes more developed as a character in later writings of the Hebrew Bible, though he appears only a few times. He at times causes humans to do bad things, as he incites King David to conduct a census (1 Chronicles 21:1).
Satan also acts as a heavenly prosecuting attorney, bringing charges against sinners before God's heavenly court. For example, in Psalm 109:6 the author asks Satan to bring an enemy to trial. Also in Zechariah 3:1-2, Satan stands at the right hand of an angel to bring charges against the High Priest. Satan has a similar role in the opening chapter of Job, where he appears in the heavenly court with the sons of God to bring charges against Job.
In the New Testament, Satan plays a much larger role. Here Satan, also frequently called the Devil (from Greek diabolos, also meaning "adversary") is a proper name for the one who opposes God. Satan is also identified in the New Testament with the deceitful serpent in Eden, as well as many other names including Belial, the evil one, the ruler of the demons, the enemy, the ruler of this world, and Beelzebul (Beelzebub, meaning "Lord of the flies," is a pun on the name Beelzebul, meaning "Prince Baal").
Many scholars attribute Satan's development from an adversary to the archenemy of God to the influence of the Persian religion Zoroastrianism. This religion is a lot like Star Wars, in which two opposing forces, one good and the other evil, struggle for control of the universe. Yet, the New Testament preserves the Hebrew Bible's notion of Satan as far inferior to God and needing to get God's permission before "raising hell" on earth (see, for example, Luke 22:31). Following the biblical period, Medieval theologians reinterpreted passages such as Isaiah 14 and Ezekiel 28, in which Babylonian and Phoenician kings are condemned for pride, as descriptions about Satan. In fact, the name Lucifer comes from a Latin translation of Isaiah 14:12, in which the Babylonian king is linked to a fallen Morning Star, called in Latin lucern ferre ("bearer of light").
