'Unclean Spirits' in the Bible

And they were all amazed, so that they questioned among themselves, saying, What is this? What new teaching 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 Jesus forthwith gave them leave. And the unclean spirits going out, entered into the swine, and the herd rushed down the steep into the sea, (they were about two thousand) and were choked in the sea.

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