In the synagogue there was a man possessed by a demon, an impure spirit. He cried out at the top of his voice, “Go away! What do you want with us, Jesus of Nazareth? Have you come to destroy us? I know who you are—the Holy One of God!”  Luke 4:33-34

            It could be that demons were always in people and Jesus pushed back their stronghold.  Another possibility is that Satan ramped up his attacks on people when Jesus was born on the earth.  The strategy only backfired giving Jesus more opportunity to showcase his authority over the demonic world.