'Unclean Spirits' in the Bible

And they were all amazed, so that they questioned among themselves, saying, What thing is this? what new doctrine is this? for with authority he commandeth even the unclean spirits, and they obey him.

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

And forthwith Jesus gave them leave. And the unclean spirits went out, and entered into the swine: and the herd ran violently down a steep place into the sea (they were about two thousand) and were choked in the sea.

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