Please Read Matthew 8:16 12:22-23 Luke 4:33-37
Long before lies were taught about evil spirits in movies Jesus made known the truth about demons. With a simple word he commanded them to come out of people and healed them. That's right, they actually live in people, making their lives miserable. There's many weird speculations about who demons are and where they come from. But the only record in the Bible of spirits becoming evil (other than Satan the Devil) and where they came from is in Genesis chapter 6 where the sons of God (angels) came down to earth and had sexual relations with women. They took wives for themselves, any of whom they chose, and even had children by them. (Genesis 6:1-4 Jude 1:6) These children of fallen angels (demons) became the world's legendary bad dudes of old.
Our world has been plagued by the presence of great evil for millenniums. Mankind invited evil into our world in the beginning, in the garden of Eden when he sinned. (Romans 5:12) In the same way people today invite the harmful affects of evil spirits into their lives by toying with sin. Those who obey God and hold to the testimony of Jesus Christ are protected. They cannot be possessed or controlled by demons. Jesus protects them and covers their sins. They are born again, born of the Holy Spirit. It is impossible for them to willfully live in sin because God's seed is in them. (1 John 3:9 5:18-19) That means since evil and sin has no hold on them by God's grace neither does Satan, and they will never die. (John 3:16) For the wages of sin is death the Bible says. (Romans 6:23) But the free gift from God is eternal life through Jesus our Lord. That's why he is also called Savior. Jesus saves his followers from the harmful affects of this demon possessed world. Even death itself is conquered through him (Jesus Christ). (1 Corinthians 15:49-58) Jesus has made us more than conquerors indeed. (Romans 8:37-39)
Please Read Luke 10:17-20
Jesus also made it known that he gives mere human beings the power to command evil spirits to come out of people in his name. (Mark 16:17-18) The name of Jesus has authority. He is the son of the living Almighty God. The demons know this and shudder. (James 2:19 Matthew 8:28-34 Mark 1:22-24 ) Hence when a person becomes a true servant of Christ he/she too is given authority by Jesus over evil spirits. This doesn't mean the demons won't bother us. On the contrary they will take a special interest in you because you belong to Christ their enemy. (2 Timothy 3:12-13 Ephesians 6:12 Revelation 12:17) You too are now their enemy. But you have the upper hand in the battle because you have Christ. As long as your faith remains in him they cannot handle you. But they will keep trying you, coming through their human minions. They hope we will get fed up with persecutions and trials and just give up. They don't mind if you're a phony Christian; always professing God with your mouth, but living contrary to the faith. That kind of person has no authority over them. But a true Christian, woe! Remember, Jesus gave us authority over demons and over all the power of the enemy (Satan). That's a lot of power! Don't let it go to our heads Jesus said. Just be glad for what it means; your names are written in heaven. You have the kingdom of God and eternal life! Something your spiritual enemies wish they had never thrown away.