Demons are identified in Scripture as fallen angels who joined Satan in his rebellion. They follow Satan, doing evil and wreaking havoc. They have limited power and like Satan are already defeated (Col 2:15).
OLD TESTEAMENT – In the OT no individuals are said to have been possessed, but demonic beings were at tested. Two of the more prominent demonic beings are the Sedim and the Se’irim. The Sed are mentioned twice (Deut 32:17; Ps 106:37), as are the Se’irim (Lev 17:7; 2 Chron 11:15). These beings are referred to as “demons” and are the recipients of forbidden sacrifices. The sacrifices consisted of adults, children, or an unclean animal. Lilith and Azazel are also considered to represent the demonic. Lilith is pictured as a female associated with unclean animals and desolate places (Isa 34:14). Azazel is mentioned in connection with the scapegoat sent into the wilderness (Lev 16:8, 10, 26). An evil spirit mentioned three times (1 Sam 16:15-16; 18:10). The evil spirit was sent to King Saul to torment him.
NEW TESTAMENT – Various kinds of activity are attributed to demons. In demonic possession an individual is so affected that his actions are influenced by a demonic spirit. Terms such as “evil spirit,” “deceitful spirits,” “unclean spirits” are used to identify demons in the NT. Demonic possession has various manifestations that include: muteness (Matt 9:32; 12:22; Mark 9:17,25; Luke 11:14); deafness (Mark 9:25); blindness (Matt 12:22; John 10:21); convulsions (Mark 1:26; 9:26); superhuman strength (Mark 5:4); and self-destructive behavior (Matt 17:15). The NT does not separate the actions of the person from those of the demon. Physical changes such as masochism (Mark 5:5) and an unnatural voice (Mark 5:7) are understood as the demon’s control of the individual. Paul understands demons as idols that men sacrifice to and worship (1 Cor 10:20-22). END OF PART 1