Matthew 12:44, Then he [the demon] said, I will return into my house from where I came out; and when he is come, he finds it empty, swept and garnished.

          The man who was delivered was empty, swept and garnished. He looked alright but his spirit had no resistance to the demon. So the demon found seven more worse than himself and possessed the man. Jesus said that the end of that man was worse than the first.

                 This story about devils living in and coming and going in and out of people was told by the Lord Jesus Himself.