Note: All Scripture quotations found in this article are from the text of the Authorized King James Version of the Bible.
Devils are likened unto flies and their leader is Beelzebub(Satan), which means "lord of the flies". They are also likened unto unclean birds. Devils, unlike angels, have wings.
Matthew 12:24 "But when the Pharisees heard it, they said, This fellow doth not cast out devils, but by Beelzebub the prince of the devils."
Ecclesiastes 10:1 "Dead flies cause the ointment of the apothecary to send forth a stinking savour: so doth a little folly him that is in reputation for wisdom and honour. 20 Curse not the king, no not in thy thought; and curse not the rich in thy bedchamber: for a bird of the air shall carry the voice, and that which hath wings shall tell the matter."
Revelation 18:2 "And he cried mightily with a strong voice, saying, Babylon the great is fallen, is fallen, and is become the habitation of devils, and the hold of every foul spirit, and a cage of every unclean and hateful bird."
Devils are small and many can indwell within one person.
Mark 5:9 "And he asked him, What is thy name? And he answered, saying, My name is Legion: for we are many." (Matthew 5:1-9)
Devils can cause physical, emotional and mental disorders.
Matthew 12:22 "Then was brought unto him one possessed with a devil, blind, and dumb: and he healed him, insomuch that the blind and dumb both spake and saw."
Luke 13:11 "And, behold, there was a woman which had a spirit of infirmity eighteen years, and was bowed together, and could in no wise lift up herself."
(Mark 5:1-7)
They also can seek to bring suicide.
Mark 9:17: And one of the multitude answered and said, Master, I have brought unto thee my son, which hath a dumb spirit; 18 And wheresoever he taketh him, he teareth him: and he foameth, and gnasheth with his teeth, and pineth away: and I spake to thy disciples that they should cast him out; and they could not. 19 He answereth him, and saith, O faithless generation, how long shall I be with you? how long shall I suffer you? bring him unto me. 20 And they brought him unto him: and when he saw him, straightway the spirit tare him; and he fell on the ground, and wallowed foaming. 21 And he asked his father, How long is it ago since this came unto him? And he said, Of a child. 22 And ofttimes it hath cast him into the fire, and into the waters, to destroy him: but if thou canst do any thing, have compassion on us, and help us."
Devils inspire false prophets and promote false doctrine.
1 John 4:1 "Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world. 2 Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God: 3 And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world."
1 Timothy 4:1 "Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils;"
They want to take the truth away from people. Example: New Versions
Matthew 13:4 "And when he sowed, some seeds fell by the way side, and the fowls came and devoured them up:"
Devils can work miracles to deceive people.
2 Thessalonians 2:7 "For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way. 8 And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming: 9 Even him, whose coming is after the working of Satan with all power and signs and lying wonders,"
Revelation 16:13 "And I saw three unclean spirits like frogs come out of the mouth of the dragon, and out of the mouth of the beast, and out of the mouth of the false prophet. 14 For they are the spirits of devils, working miracles, which go forth unto the kings of the earth and of the whole world, to gather them to the battle of that great day of God Almighty."
Devils deceive and cause confusion.
Acts 16:16 "And it came to pass, as we went to prayer, a certain damsel possessed with a spirit of divination met us, which brought her masters much gain by soothsaying: 17 The same followed Paul and us, and cried, saying, These men are the servants of the most high God, which shew unto us the way of salvation. 18 And this did she many days. But Paul, being grieved, turned and said to the spirit, I command thee in the name of Jesus Christ to come out of her. And he came out the same hour."
Devils are attracted to fire and water. The marks for someone who is devil possessed is being around dead bodies, unnatural strength, nakedness and self-mutalation. Please read all of Mark 5.
Matthew 17:15 "Lord, have mercy on my son: for he is lunatick, and sore vexed: for ofttimes he falleth into the fire, and oft into the water."
Contrary to popular belief, unclean spirits can effect saints, not just the unsaved. Our soul is saved, but our flesh and mind can still be effected by the devil. (2 Cor. 10:1-5)
Acts 5:1 "But a certain man named Ananias, with Sapphira his wife, sold a possession, 2 And kept back part of the price, his wife also being privy to it, and brought a certain part, and laid it at the apostles' feet. 3 But Peter said, Ananias, why hath Satan filled thine heart to lie to the Holy Ghost, and to keep back part of the price of the land?"
Ephesians 4:27 "Neither give place to the devil."
(Matthew 16:21-23)
Hell is the future for the devils and they are aware of this fact.
Matthew 8:28 "And when he was come to the other side into the country of the Gergesenes, there met him two possessed with devils, coming out of the tombs, exceeding fierce, so that no man might pass by that way. 29 And, behold, they cried out, saying, What have we to do with thee, Jesus, thou Son of God? art thou come hither to torment us before the time?"
They recognize the Lord Jesus Christ, his servants and also believe there is one God.
James 2:19 "Thou believest that there is one God; thou doest well: the devils also believe, and tremble."
(Mark 1:23-24, Acts 19:13-19)
As Christians we can arm ourselves against devils with the name of Jesus Christ, the armor of God and prayer.
(Matthew 7:22-23, Ephesians 6:10-18)