Satan
Among the angelic spirits of the unseen world there are those that are found, though the Bible nowhere records how they fell into such a condition. The chief of these evil angelic spirits is one known as the adversary - the adversary of God, his people, and all that is good. The Hebrew word for ‘adversary’ is Satan, which later became the name used in the Bible for this leader of evil (Job 1:6). He is also call the devil (Matt 4:1-22; 1 John 3:8, Rev 12:9), the prince of demons (Matt 9:34, 12:24, see also Beelzebub), the prince of this world (John 12:31;14:30, 16:11), the god of this world (2 Cor 4:4), the prince of the power of the air (Eph 2:2) and the accuser of the brethren (Rev 12:10; cf. Job 1:6-12, Zech 3:1).
God’s Rebellious servant
We should not think that Satan is in some way the equal of God, one being a good God and the other an evil God. God alone is God (Isa 44:6). Satan is no more than an angelic being created by God. There are good angels and evil angels. Satan being chief of the evil ones (Matt 25:31,41 Eph 6:12; Jude 9; Rev 12:7-9; see Angels; Demons). God, however is above and over all.
Also, there are not, as it were, two kingdoms, a kingdom of good where God is absolute ruler and a kingdom of evil where Satan is absolute ruler. Satan is not a sovereign ruler but a rebel. Like all created beings, he is under the rule and authority of God and he can do his evil work only within the limits God allows (Job:12; 2:6, cf. Rev 20:2-3; 20:7-8). He is till the servant of God, even though a rebellious one (Job 1:6-7, 2:1-2, Zech 3:1-2). In spite of the evil he loves to do, he is still fulfilling God’s purposes, even though unwilling (Job 1:9-12, 1 Kings 22:19-23; cf. John 13:2,27); Acts 2:23, 1 Cor 5:5; 2 Cor 12:7; 1 Tim 1:20).
This does not mean that God tempts people to do evil. It is Satan, not God who is the tempter (Gen 3:1-6, Chron 21:1`; Matt 4:1-11; 1 Cor 7:5; James 1:13). God desires rather to save people from evil (Matt 6:13; 1 Cor 1:13). Yet God allows them to suffer the troubles and temptations that Satan brings in life for through such things he tests and strengthens their faith (James 1:2-3,12; cf Heb 2:18; 5:8-9; see Temptation, Testing)
Satan is hostile to God and fights against God’s purpose (Matt 4:1-12, Mark 8:31-33). But in the long run, Satan cannot be successful, because Jesus Christ, by his life, death and resurrection, has conquered him, and delivered believers from his power (Matt 12:29-29, Luke 10:18, John 12:31, 16:11, Acts 26:18, Col 2:15, Heb 2:14-15, 1 John 3:8). (Concerning Jesus Christ’s conquest of Satan see Kingdom of God).
Man’s Enemy
Although Jesus has conquered Satan, the world at present sees neither Jesus’s conquest nor Satan’s defeat. God allows evil angels to continue to exist just as he allows evil people. He has condemned them but not yet destroyed them. The world will see Jesus’s conquest and Satan’s defeat in the great events at the end of the age, when Christ returns in power and glory (Rev 20:10).
In the meantime, Satan continues to operate (Matt 13:24-26; 37-39). He opposes all that is good and encourages all that is evil. At times he works with brutality and ferocity (1 Peter 5:8; Rev 2:10) at other times with cunning and deceit (2 Cor 2:11; 11:14; 1 Tim 3:7). He works not only through people who are obviously evil (Acts 13:8-10, Eph 2:1-3, 1 John 3:10-12, Rev 2:13), but also through those who appear to be good (Mark 8:33; John 8:44; Acts 5:3; Rev 2:0, 3:9).
Satan causes people physical suffering through disease (Luke 13:16; 2 Cor 12:7; see Disease), and evil Spirits (Mark 3:20-27). He brings mental and spiritual suffering through the cunning of his deceit and temptations (1 Cor 7:5, 2 Thess 2:9-10; 2 Tim 2:24-26). Above all, he wants to prevent people from understanding and believing the gospel (Matt 13:19, 2 Cor 4:4).
Christians, because they have declared themselves on the side of God, may at times experience Satan’s attaches more than others. They have a constant battle against Satan, but they do not fight entirely by their own strength. Certainly, they must make every effort to resist Satan, and avoid doing those things that will give Satan an opportunity to tempt them (Eph 4:27, James 4:7). But God gives Christians the necessary armor to withstand Satan’s attacks (Eph 6:11-13).
Just as Satan opposed Jesus’s in his ministry, so he will oppose Jesus’s followers in their ministry (John 8:42-44 Acts 13:10; 1 Thess 2:18). But through the victory of Jesus, they too can have victory (Luke 10:17-18; 22:31-33, Rev 12:1-11).