The Fallen Angels (Demons)
These beings, because of pride, did not return God's love. God did not destroy them, but permits them a limited scope of activity. Their condition is permanent for no creature can turn away from the perfect good of the beatific vision once he has come to enjoy it, and no additional reflection could change the mind of a purely spiritual being who has turned away.
Demons are fallen angels under the command of Satan, those who are still free after the Gen. 6 affair. Satan is called the Prince, or Ruler, of all demons in Matthew 9:34; 12:24; Mark 3:22; Luke 11:15. Demons are also called the ministers, or ambassadors of Satan, Luke 4:35; 9:1,42; John 10:21. Satan is brilliant, an administrative genius. He has an excellent organization, mentioned in Eph. 6:10-12 (READ) The Bible also makes a distinction between demon possession and demon influence.