'Unclean Spirits' in the Bible

And they were all amazed, insomuch that they questioned among themselves, saying, What is this? a new teaching! with authority he commandeth even the unclean spirits, and they obey him.

And the unclean spirits, whensoever they beheld him, fell down before him, and cried, saying, Thou art the Son of God.

And he gave them leave. And the unclean spirits came out, and entered into the swine: and the herd rushed down the steep into the sea, in number about two thousand; and they were drowned in the sea.

And he calleth unto him the twelve, and began to send them forth by two and two; and he gave them authority over the unclean spirits;