Before the physical realm, God created powerful spirit servants who are referred to in Scripture as angels, literally meaning "messengers" (Hebrews 1:7, Hebrews 1:14). Described in some verses as "sons of God" by virtue of their creation by God, they witnessed the formation of the earth (Job 38:4-7).

There are hundreds of millions of righteous angels serving God (Revelation 5:11). But a large contingent of angels rebelled against God prior to the creation of mankind. They chose the way of vanity and selfishness instead of God's way of outflowing love for others. The leader of this rebellion is now known as Satan. He and his evil cohorts are referred to in the New Testament as unclean spirits or as demons.

Satan is the adversary of God, as the name Satan actually means "adversary" in the Hebrew of the Old Testament. The Greek Septuagint translation of the Old Testament renders this word as diabolos, from which we get the English word devil. It means "slanderer" and can have the sense of an accuser or opponent in court (compare Zechariah 3:1). Both the Hebrew and Greek terms are used in the New Testament.

The devil opposes God continually at every opportunity. He despises God's plan, particularly its objective of adding human beings to God's family. Hence, Satan also detests human beings. He is the deceiver and accuser of the brethren (Revelation 12:9-10). He is a murderer and a liar and the father of lying (John 8:44). He is described figuratively as a roaring lion seeking whom he may devour (1 Peter 5:8).

Satan is not an ordinary opponent. He is an extremely resourceful and cunning adversary whose ultimate goal is to deny salvation to mankind by deceiving people, leading them astray, enticing them to sin and turning them against God (Ephesians 6:11-18; 2 Corinthians 2:11; Luke 8:12).

As the book of Job demonstrates, Satan can act only within the limits permitted by God (Job 1:12; Job 2:6). Job's account also illustrates Satan's accusatory attitude and clearly describes him as a specific individual personality and literal being. As the New Testament shows, he later came to Jesus Christ as a literal being in an unsuccessful effort to tempt Jesus into selfish concern (Matthew 4:1-11).

Just as Satan's actions are limited by God's will, his time is also limited. He is presently "the ruler of this world" (John 12:31; John 14:30; John 16:11) and described as "the god of this age" (2 Corinthians 4:4), but his reign will come to an end at the seventh and last trumpet when Jesus Christ returns (1 Corinthians 15:52; 1 Thessalonians 4:16; Revelation 11:15).

Satan will then be removed and bound throughout the millennial reign of the Messiah but will be released for a short while at the end of the 1,000 years (Revelation 20:1-3; Revelation 20:7-8). After that he will be permanently removed when he is "cast into the lake of fire and brimstone" (Revelation 20:10), which is "prepared for the devil and his angels" (Matthew 25:41).

Satan was created as an angel of high position and authority. In Isaiah 14:12 he is called in Hebrew Heylel, followed by the distinction "son of the morning." The Latin translation of the name here is given as Lucifer, a name for the planet Venus when appearing as the morning star, meaning "light bearer." Some versions therefore translate the words here as "star of the morning," "bright star" or "morning star" (New American Standard Bible, Revised English Bible, New International Version).

Addressed in Ezekiel 28 as the "king of Tyre," as he is the unseen power behind the throne of earthly kingdoms, this being was initially an "anointed cherub who covers" (Ezekiel 28:14-16), one of two angelic beings whose wings were stretched out over the throne of God, as represented in the earthly copy, the Ark of the Covenant (see Exodus 25:20-21; Hebrews 9:23-24; Revelation 11:19). He evidently had at least equal rank with Michael, an "archangel" and "great prince" (Jude 1:9; Daniel 12:1).

Lucifer was created perfect and blameless, but eventually chose the way of sin and rebellion (Ezekiel 28:12-17). Apparently a third of the angels followed him in his insurrection and with him attempted to overthrow God, but they were defeated and cast down to the earth (Revelation 12:4; Luke 10:18; Isaiah 14:12-15; 2 Peter 2:4). The kingdom of Satan is now characterized by darkness, not light, though Satan is able to deceptively present himself as an angel of light (Luke 22:53; Ephesians 6:12; Colossians 1:13; 2 Corinthians 11:14).

Under some circumstances, the devil and his demons are able to gain possession and control of human beings and even animals (Matthew 8:28-33; Matthew 9:32-34). Satan himself entered and possessed the traitor Judas (Luke 22:3). Christ, whose authority is greater than Satan's, cast out demons during His ministry on earth and has empowered His duly ordained servants to do the same (Mark 16:17).

Satan is referred to by different names and descriptions that denote some of his evil roles, characteristics and actions. Besides "the devil," he is also called Apollyon and Abaddon, meaning "destroyer" and "destruction," respectively (Revelation 9:11); Belial, meaning "worthless" or "wicked" (2 Corinthians 6:15); Beelzebub, the name of a Philistine god meaning "Lord of flies" (Matthew 12:24-27, compare 2 Kings 1); the great dragon and serpent (Revelation 12:9); the tempter (Matthew 4:3; 1 Thessalonians 3:5); and the prince of the power of the air (Ephesians 2:2).