Thought on casting out demons

Mark 1:27 "And they were all amazed, so that they questioned among themselves, saying, "What is this? A new teaching with authority! He commands even the unclean spirits, and they obey him."
Jesus did something new when He healed by casting out demons- He brought evidence of Spiritual authority.There are only two logical explanations for that kind of authority that the demons obey. One is that He is the prince of demons. Obviously Satan has dominion over the demons and can command them, and have them obey him. This is the conclusion the Pharisees came to,

Matthew 9:33-34 "And when the demon had been cast out, the mute man spoke. And the crowds marveled, saying, "Never was anything like this seen in Israel." But the Pharisees said, "He casts out demons by the prince of demons.

That does explain part of it, the power, but it fails to explain the motive, for what reason would Satan have to cast demons out of people and restore them to health? If anything Satan would want as many people bound and kidnapped into darkness as possible. It's this very point Jesus addresses in

Luke 11:17-19 "But he, knowing their thoughts, said to them, "Every kingdom divided against itself is laid waste, and a divided household falls. And if Satan also is divided against himself, how will his kingdom stand? For you say that I cast out demons by Beelzebul." 

Which only leaves us with the other possibility to explain why Jesus has both the authority and motive for casting out demons: Jesus is God. 
 
Jesus is God.