Jesus taught people various things about demons.

Luke 11:14-28

14 One day there was a man there who, because a demon controlled him [MTY], was unable to speak. After Jesus expelled the demon, the man began to talk. Most of the people there were amazed. 15 But some of them said, “It is Beelzebub, the ruler of the demons, who enables this man to expel demons!” 16 Other people there asked Jesus to perform a miracle to prove ◄he was the Messiah/that he had come from God► [MTY/EUP]. They wanted to trap him into not being able to perform a miracle or into doing something ridiculous. 17 But Jesus knew what they were thinking. So he said to them, “If the people in one nation fight against each other, their nation will be destroyed {they will destroy their nation}. If the people in [MTY] one house are divided, they will cease to remain as one family. 18 Similarly, if Satan and his demons were fighting against each other, ◄his rule over them would certainly not last!/how would his rule over them last?► [RHQ] I say this because you are saying that I am expelling demons by the power of the ruler of his own demons 19 Furthermore, if it is true that Satan enables me to expel demons, is it also true that your disciples who expel demons do so by Satan’s power [RHQ]? No, that is not true. So they will show that you are not thinking logically. 20 But because it is by the power [MTY] of God that I expel demons, I am showing you that the power of God to [MET] rule people’s lives has come to you.”

21 Then, to show that by expelling evil spirits he was making it clear that he was much more powerful than Satan, Jesus said [MET], “When a strong man who has many weapons guards his own house, no one can steal the things in his house. 22 But when someone else who is stronger attacks that man and subdues him, he is able to take away the weapons in which the man trusted. Then he can take from that man’s house anything he wants to. 23 No one can be neutral. Those who do not help me are opposing me, and those who do not gather people to become my disciples are causing those people to go away from me.”

24 Then Jesus said this: “Sometimes when an evil spirit leaves someone, it wanders around in desolate areas seeking someone in whom it can rest. If it does not find anyone, it says to itself, ‘I will return to the person in whom I used to live!’ 25 So it goes back and finds that the Spirit of God is not in control of that person’s life. The person’s life is like a house that has been {that someone has} swept clean and everything put {put everything} in order, but a house that is empty. 26 Then this evil spirit goes and gets seven other spirits that are even more evil than it is. They all enter that person and begin living there. So, although that person’s condition was bad before, it became much worse.”

27 When Jesus said that, a woman who was listening called out to him, “God is pleased with the woman who gave birth to you (sg) and let you nurse at her breasts!” 28 But he replied, “God is much more pleased with those who hear his message and obey it!”