The Bible gives some examples of people possessed or influenced by demons. Their purpose is to have dimensional access to the tangible world and its resources. A spirit, which demons are, can only have so much access to man in the carnal world through the influence they can wield. Physical possession is the holy grail of control and access with respect to mankind. In this world, money, power, influence and access is all managed through mankind directly. A demon in physical and mental control of a corporal body can more effectively carry out Satan’s plans for mankind and the world and perpetuate more permanent and destructive change that cannot be accomplished by mental influence or emotional manipulation alone.
Biblical examples provide insight of demonic influence and how a demon possesses a person: (Matthew 9:32-33; 12:22; 17:18; Mark 5:1-20; 7:26-30; Luke 4:33-36; Luke 22:3; Acts 16:16-18). In some of these passages, the demon possession causes physical ailments such as inability to speak, epileptic symptoms, blindness, etc. In other cases, it causes the individual to do evil, Judas being a principle example. In Acts 16, a demonic spirit gives a slave girl some ability to know things beyond her own learning. “And it came to pass, as we went to prayer, a certain damsel possessed with a spirit of divination met us, which brought her masters much gain by soothsaying: The same followed Paul and us, and cried, saying, These men are the servants of the most high God, which shew unto us the way of salvation. And this did she many days. But Paul, being grieved, turned and said to the spirit, I command thee in the name of Jesus Christ to come out of her. And he came out the same hour.” Acts 16:16-18 The demon-possessed man of the Gadarenes, who was possessed by a multitude of demons (Legion), had superhuman strength and lived naked among the tombstones (Luke 8:26–33). King Saul, after rebelling against the LORD, was troubled by an evil spirit (1 Samuel 16:14-15; 18:10-11; 19:9-10) with the effect of a depressed mood and an increased desire to kill David. There is a wide variety of possible symptoms of demon possession, such as a physical impairment that cannot be attributed to an actual physiological problem, a personality change such as depression or aggression, supernatural strength, immodesty, antisocial behavior, and the ability to share information that one has no natural way of knowing. It is important to note that nearly all, if not all, of these characteristics may have other explanations, so it is important not to label every depressed person or epileptic individual as demon-possessed. On the other hand, Western cultures probably do not take satanic involvement in people’s lives seriously enough. In addition to these physical or emotional distinctions, one can also look at spiritual attributes showing demonic influence. These may include a refusal to forgive (2 Corinthians 2:10-11) and the belief in and spread of false doctrine, especially concerning Jesus the Christ and His atoning work (2 Corinthians 11:3-4, 13-15; 1 Timothy 4:1-5; 1 John 4:1-3). Concerning the involvement of demons in the lives of Christians, the apostle Peter is an illustration of the fact that a believer can be influenced by the devil (Matthew 16:23). Some refer to Christians who are under a strong demonic influence as being “demonized,” but never is there an example in Scripture of a believer in Christ being possessed by a demon. A Christian cannot be possessed because he has the Holy Spirit abiding within (2 Corinthians 1:22; 5:5; 1 Corinthians 6:19), and the Spirit of God would not share residence with a demon. We are not told completely and exactly how one opens himself up for possession. If Judas’ case is representative, he opened his heart to evil—in his case by his greed (John 12:6). This means it may be possible that if one allows his heart to be ruled by some habitual sin, it becomes an invitation for a demon to enter. From missionaries’ experiences, demon possession is also related to the worship of heathen idols and the possession of occult materials. Scripture repeatedly relates idol worship to the actual worship of demons (Leviticus 17:7; Deuteronomy 32:17; Psalm 106:37; 1 Corinthians 10:20), so it should not be surprising that involvement with idolatry could lead to demon possession.
Based on the above scriptural passages and some of the experiences of missionaries, we can conclude that many people open their lives up to demonic involvement through the embracing of some sin or through cultic involvement (either knowingly or unknowingly). Examples may include immorality, drug/alcohol abuse that alters one’s state of consciousness, rebellion, bitterness, and transcendental meditation. There is an additional consideration. Satan and his demons can do nothing the Lord does not allow them to do (Job 1-2). This being the case, Satan, thinking he is accomplishing his own purposes, is actually accomplishing God’s good purposes, as in the case of Judas’ betrayal. Some people develop an unhealthy fascination with the occult and demonic activity. This is unwise, if we pursue God, if we are clothing ourselves with His armor and relying upon His strength and not ours, (Ephesians 6:10-18), we have nothing to fear from the evil ones, for God rules over all!