Oh, look at this. Here you say evil spirits are fallen angels. I do agree with you, but you are making doctrines of men here. Unless you can prove this with scripture it is just your opinion.
The English transliteration of the word "demon," is pronounced "daimon," and its G/K number is 1230 (
The Strongest Exhaustive Concordance). Its definition of the word "daimon" is: evil spirit. Additionally, this fact is per Matthew 8:31, when the demons begged Jesus, "If you drive us out, send us into that herd of pigs." Also, according to Mark 5:9, when Jesus asked the demon possessed man what his name was, he responded, "My name is legion, for we are many." I should add the best estimate of a Roman legion was anywhere from 3,000 to 6,000 men; do the math. It is evident the demon possessed man had many "evil spirits" in him. So it is clear Scripture does indeed refer to demons as "evil spirits;" more specifically, so did the authors of the gospels. "Doctrine of Men"? Have you ever heard of verbal-plenary inspiration, or do you not believe the Bible to be the divine, inspired and inerrant Word of God?
We can conclude:
(1) God is spirit.
(2) Satan is Spirit.
(3) Satan is an angel.
(4) There are many fallen angels.
(5) Fallen angels must likewise be spirits.
(6) Satan and fallen angels rebel (rebelled) against God.
(7) Per Revelation 12:7-9, Satan and his angels were hurled to the earth.
(8) Satan inhabits the earth (There are numerous scriptures which confirm this fact,
but let's just take Job into consideration).
(9) Satan is an evil spirit.
(10) Fallen Angels must also inhabit the earth, per numerous scriptures.
(11) Fallen angels are also evil spirits.
(12) Demon = Evil Spirit
(13) Evil spirit(s) [According to Scripture] = Satan/Fallen Angels