'Unclean Spirits' in the Bible

And they were all astonished, so that they were inquiring one to another, saying, What is this? what new teaching is this? Because according to authority He commands the unclean spirits, and they obey Him;

And unclean spirits, when they saw Him, fell down before Him, and were crying out, saying, Thou art the Son of God.

And Jesus immediately permitted them. And the unclean spirits having gone out, came into the swine: and the herd rushed down a precipice into the sea, and there were about two thousand: and they were strangled in the sea.

And He calls the twelve to Him, and began to send them out two by two; and He gave them authority over unclean spirits.