In the Greek New Testament, angels are always masculine gender, now if demons are fallen angels, then demons would be masculine gender, but demons are neuter gender, that proves the truth that demons are not fallen angels.
The truth is, demons come from the inside of a person, the Messiah said that evil comes from within (Mark 7:21-23).
Many people say demons are fallen angels, but is that true? In the New Testament, the Greek word for the word “devils”, “unclean spirits” and “evil spirits” is neuter gender, and the word for angel & devil is Masculine gender, if fallen angels were demons, then they would be masculine, not neuter.
In Mark 1:23-26, the unclean spirit (verse 23), in the man, is neuter gender, in verse 25, “Yeshua rebuked him (masculine singular), saying, hold thy peace, and come out of him (masculine singular), verse 26 “and when the unclean spirit had torn him (masculine), and cried with a loud voice, came out of him (masculine).
The Greek word “akathartos” for the word “unclean” means “tainted by sin.” “devils” are unclean spirits, unclean spirits are a result of sin, the flesh is under the power of sin (Romans 7:17-25) that’s where demons come from, that truth is confirmed in what God says in James 3:16.
James 3:16 For where envying & strife (self seeking exist) there is confusion & every evil work.
In Luke 4:33 it says the man had a spirit of an unclean devil (demon), the words “unclean devil (demon)l” are neuter.
Mark 1:23-26 And there was in their synagogue a man [masculine] with an unclean spirit [neuter]; and he cried out,
:24 Saying, Let us alone; what have we to do with thee, thou Yeshua of Nazareth? art thou come to destroy us? I know thee who thou art, the Holy One of God.
25 And Yeshua rebuked him [masculine], saying, Hold thy peace, and come out of him [masculine].
:26 And when the unclean spirit [neuter] had torn him [masculine], and cried with a loud voice, [he] came out of him.
In the Greek text, the Stephanus Textus Receptus (1550 with accents), it does not say “he came out of him.” the translators added the word “he”, the unclean spirit cannot be a “he” because it is neuter gender, which means the man was not possessed by a fallen angel, he was possessed by the unclean spirit that was inside of him.
Yeshua rebuked the man, not the unclean spirit, unclean spirits are the result of sin, that truth is confirmed by what Yeshua says in Mark 7:21-23.
Mark 7:21-23 For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders,
:22 Thefts, covetousness, wickedness, deceit, lasciviousness, an evil eye, blasphemy, pride, foolishness:
:23 All these evil things come from within, and defile the man.