Last Monday, we explored the origin of demons, and I think, for many, it was an unsatisfying blog as there were very few concrete answers. There is more to go off of here as we explore the question What do demons do? but still some of the activity that we attribute to demons is nowhere to be found in the Bible. Now, if we experience something evil that is not explained in the Bible, that’s not to say that it’s not demonic, but that should make us hold our judgment and study further.
Disclaimer: This is a long blog, but I hope it’s as interesting to you to read as it was for me to write.
Like we saw last time, the words Satan and devil can be translated as “adversary,” and I think that’s primarily the goal of Satan and his demons. They are enemies of God’s plan, which we saw in Ephesians 1:9-10 (cf. Colossians 1:20) is to unite all things in Christ to himself. Since this union to Christ comes through faith in Christ, it seems that the highest priority of demons is to try to destroy faith—to stop unbelievers coming to faith in the first place and to lead believers to reject their faith.
So, what are some of the tactics that demons use?
Satan is not called the father of lies for nothing (John 8:44; cf. Revelation 12:9). We see demonic deception in several ways in the world. 1) Very generally, Satan blinds unbelievers to the gospel (2 Corinthians 4:3-4). 2) Demons seem to be the power behind other religions, acting as their gods (Deuteronomy 32:16-17; 1 Corinthians 10:20). They also seem to empower idol worship, magic, etc. We shouldn’t be skeptical that people actually experience unexplainable things (even good things) in other religions and the occult; there is spiritual power there. 3) Demons also try to deceive Christians through false teachers. Paul picks up on this in 2 Corinthians 11:
For if someone comes and proclaims another Jesus than the one we proclaimed, or if you receive a different spirit from the one you received, or if you accept a different gospel from the one you accepted, you put up with it readily enough. . . . For such men are false apostles, deceitful workmen, disguising themselves as apostles of Christ. And no wonder, for even Satan disguises himself as an angel of light. So it is no surprise if his servants, also, disguise themselves as servants of righteousness. Their end will correspond to their deeds. (vv. 4, 13-15).
Satan and his demons are not ignorant. They know that the closer they can bring teaching that sounds like Christian truth (but is the devil’s lie), the more Christians will be led astray by it. Satan even used Scripture when he was tempting Jesus (Matthew 4:6)! Paul declares that this deception will increase as the end is drawing near (1 Timothy 4:1-2).
Alex’s Speculation Corner #1: In speaking of demonic empowerment of false religion, let’s consider something. We all know that the Western world is very skeptical of anything supernatural, and many of us have heard that the rest of the world claims to experience the supernatural frequently. But demons are set on deception by empowering false worldviews. Do you think that they are going to work in obvious ways in the West? Or do you think that they hide their activity here to deceive people into thinking that the spiritual world does not exist? I think that this is the case. Truthfully, if I saw something clearly demonic happening, that is only going to be a bolster to my faith! What this means for me is that materialism is probably just as much of a demonically empowered worldview as something like Hinduism or sorcery.
Temptation to sin seems to be grounded in Satan’s role as an “accuser” (Revelation 12:10). If they can get people to sin, Satan and his demons feel that they have the ability to accuse them before God. These accusations can shake the faith of even the most solid believers. Temptation is seen most prominently in Satan’s temptation of Jesus in the wilderness (cf. Matthew 4:1-11). With God’s ultimate plan to unite everything in Christ, God has given the loving unity of the church family and marriage as signs that point to that plan (Ephesians 3:6-11; 5:31-33). Temptations that lead to discord in the church and the destruction of marriage are priorities for the demonic realm (2 Corinthians 2:6-11). In 1 Corinthians 7:5, Paul says that married couples should not deprive themselves of sexual intimacy for too long or else Satan may tempt them because of a lack of self-control.
This has been about what we are tempted to do, but how do the evil forces actually tempt us? That leads me to . . .
Alex’s Speculation Corner #2: Many of us believe that Satan and demons tempt us by putting thoughts into our heads. But I’m skeptical about this (and I could be wrong). From meditating on the Biblical evidence, I can find no convincing evidence to support the conclusion that Satan or demons can put thoughts into someone’s head without possessing them. And, as I’ll discuss in a bit, demons probably cannot possess someone with the Holy Spirit. Some of the verses used in defense that demons can do this are 1) Matthew 16:22-23 where Peter says that Jesus would not suffer, and Jesus responds, “Get behind me, Satan.” But the apostles had yet to receive the Holy Spirit (John 20:22; Acts 2:3-4). Perhaps the strongest Biblical argument is 2) the story of when Ananias and Sapphira sold their property and kept a portion of it for themselves. They lied when Peter asked if it was the full amount. Peter said that Satan had filled Ananias’s heart and that he had lied to the Holy Spirit (Acts 5:3). But the Scriptural evidence works against the idea that Ananias had the Spirit at all. In Acts 4:32-35, it says that all of those who believed were selling property and laying the proceeds at the apostles’ feet. Then 5:1 starts with “But a man named Ananias,” which casts doubt on whether he was a true believer in the first place. But then, in 5:4, Peter says that Ananias had lied not to people (the apostles) but to God, which seems to point to the idea that when Peter said Ananias lied to the Spirit, it was the Holy Spirit in the apostles and the church, not in himself.
So, how does Satan tempt believers? I think the answer is found in Ephesians 2:1-3. Satan and his demons orchestrate things in the world so that the things and events around us are tempting to our flesh (and remember they can place thoughts in unbelievers’ minds). And those of us who are saved are now free to choose to walk in the Spirit, but we can also, disobediently, choose to walk in the flesh (Galatians 5:13). And so, when we give in to temptation, we are choosing to follow the desires of our flesh that have been triggered by demonic schemes. This is made clear in James 3:14-15 when James places all of the blame for our sin on our own evil desires. In conclusion, I lean towards thinking that no evil power can put thoughts in your mind unless they possess you, and believers with the Holy Spirit cannot be possessed.
Possession occurs when an evil spirit inhabits a human. Why demons possess people is an interesting question, but it probably has something to do with the faith-crippling effects of fear. Those who live in great fear of the demonic realm are more apt to practice many different religions—any religion that can help them deal with their demonic oppression. And if the spiritual bondage is heavy, it can make them lose faith that freedom is even possible.
Most possession tends to come with some kind of physical/mental disease. “ . . . nakedness, mental anguish, and masochism (Matt. 8:28-33; cf. Mark5:1-10; Luke 8:26-39); inability to speak (Matt. 9:32; 12:22); blindness (Matt. 12:22); lunacy [insanity—the verb often translated seizures may also imply hallucinations] (Matt 4:24; Mark 9:17).” Now, this does not mean that every physical or mental illness is demonic, but that they have the power to do this.
A problem: With as little as is said about demons, there are some passages that throw a wrench into everything. And even now, I’m debating myself on some of what I said above. One of these is Paul’s thorn: “So to keep me from becoming conceited because of the surpassing greatness of the revelations, a thorn was given me in the flesh, a messenger of Satan to harass me, to keep me from becoming conceited. Three times I pleaded with the Lord about this, that it should leave me” (2 Corinthians 12:7-8). Many people take this as a physical/mental ailment of Paul’s, in which the question is could a “messenger of Satan” (can also be translated “angel of Satan”) cause ailments in believers? There seems to be some experiential evidence for this as missionaries and church planters have been heard to experience extreme illnesses after they get to the mission field. But the Scripture also says that this thorn in the flesh is a messenger of Satan that harasses him. Some of the most popular early church fathers said that this was not a physical ailment, but people (in the flesh) that Satan was using to persecute him and hinder his ministry. This second option actually fits the context of vv 7-10. In the end, this has been a contested passage for 2000 years, and we can’t form doctrine off a passage that is unclear.
Alex’s Speculation Corner #3: Here are the verses that suggest to me that Christians cannot be possessed by a demon if they have the Holy Spirit—besides the reality that there is no clear biblical instance of a believer being possessed. 1) Matthew 12:28: Jesus says that his casting out demons by the Holy Spirit was evidence that the kingdom of God had come. The Spirit is God’s kingdom presence in believers (Ephesians 2:21-22). 2) Matthew 12:43-45 is Jesus telling the story about an exorcised demon roaming the world and coming back to the person he used to possess and finding the house “empty.” And then he brings seven of his demon buddies with him. Someone with the Holy Spirit does not have an empty house. 3) 1 John 4:4: John says that believers have overcome all false spirits because the one who is in them is stronger than he who is in the world. Despite the possible complications made by the passage on Paul’s thorn, it seems that demons can certainly harass and tempt and deceive believers externally, but they can’t possess them. The question still remains whether they can afflict them physically.
Another thing that Satan and demons cannot do is perhaps the most important. They cannot do anything that God will not allow them to do. We saw that Paul’s thorn could only stay if God allowed it. But the clearest example of this is Job. Satan had to ask God permission to afflict Job (and not only that, he asked God for God himself to afflict Job. But God allows Satan to do it). He could not do anything without God’s permission. And I think there is also a note for us on demonic physical illness here. You can’t be afflicted with a disease or ailment unless God gives the demonic realm permission. And generally, if we are in Christ, we can rest in this: that if we are under any kind of demonic attack, God has allowed it for our good and sanctification (Romans 8:28-29). And we can throw that right in the enemy’s face; his attacks are working against his own plans.
 Many would then ask whether denominations are Satanic or whether churches should split over certain issues. But as we saw earlier, Satan is an intelligent enemy. He can bring in false teachers and deceive some, but then those who call out the false teaching are called divisive by the deceived. Then, the results could either be a split or a sinful accommodation to false doctrine. The church is to be united in the truth (Ephesians 5:11-15). Who decides what’s worth splitting over? It is the pastors who are called to account by God for how they protected both the purity of the doctrine of the church and the unity of love among the flock of God (Acts 20:28-31; Hebrews 13:17).
 S.E. McClelland in the Evangelical Dictionary of Theology: Third Edition