The English transliteration of a Greek term (daimōn) originally referring to any one of numerous, vaguely defined spirit beings, either good or bad. In the nt the term is reserved for evil spirits who are opposed to God and God's people. Furthermore, in the nt, the expressions "demon," "unclean spirit," and "evil spirit" appear to be interchangeable terms for the same entities. In the kjv, demons are referred to as "devils," but in most other English translations, the word "devil" is used only for Greek diabolos, not daimōn; thus there is one devil, but multiple demons.

In the ancient world, there was widespread belief in spiritual powers or beings that existed in addition to the well-known gods and goddesses. These beings were not understood as necessarily evil, though some might be. The idea that many or even all such beings were allied with the forces of darkness and wickedness only came into focus during the Second Temple period, probably under the influence of Persian thought. There are traces of the belief in harmful spirits in the earlier biblical writings (e.g., Gen. 6:1–4; Lev. 16:6–10, 26; Isa. 34:14; Job 6:4; Ps. 91:5), but little was made of this idea in Hebrew thought until the late postexilic period. Then the belief developed that there existed not only numerous evil spirits or demons, but also a leader for these evil forces. This leader came to be known by several titles, though the most common designation was Satan (the Greek title diabolos, "the devil," was then used as a virtual synonym for Satan, as, e.g., in John 8:44). As a result of this type of thinking, the idea developed that there were armies of demons, under the leadership of Satan or the devil, doing battle with God and God's allies.

Further development led to the idea that demons could invade human bodies and cause mental illness, physical disease, or other specific problems such as deafness or blindness (e.g., Matt. 9:32; Mark 9:5; Luke 6:18; 9:42; 11:14). Some even believed that demons could take control of nature and cause natural calamities and disasters. Such ideology is clearly reflected in the Synoptic Gospels, where Jesus is known as one who characteristically exorcises demons (e.g., Matt. 8:28–34; Mark 5:1–20; Luke 8:26–39; Matt. 12:22–32; Mark 3:22–27; Luke 11:14–23). Likewise, Jesus's disciples are given authority to exorcise demons (Matt. 10:1, 8; Mark 3:14–15; 6:7; Luke 9:1; cf. Mark 9:38–39), the Pharisees are said to exorcise demons (Matt. 12:27), and, in the book of Acts, spirit-filled leaders of the early church exorcise demons (5:16; 8:7; 19:14–16). In John's Gospel, there are no references to exorcism, but Jesus's opponents do claim that he is demon-possessed (7:20; 8:48; cf. 10:19–21); a similar charge was leveled in the Synoptic Gospels with reference to both Jesus (Mark 3:30) and John the Baptist (Matt. 11:18; Luke 7:33).

References to demons occur in numerous contexts. In the Gospel of Mark, Jesus must silence demons or else they will reveal that he is the Son of God (Mark 1:23–25, 34; 3:11–12; cf. Luke 4:41). The reality of Jesus's exorcisms indicate that the kingdom of God has come (Matt. 12:28; Luke 11:20). The claim that Jesus casts out demons by the power of Beelzebul, the prince of demons, is identified as blasphemy of the Holy Spirit, an unforgivable sin (Mark 3:22, 29). Jesus teaches that once a demon goes out of a person, it travels through desert areas and then returns, bringing seven more, if its former home is vacant. Success at casting out demons is not the most appropriate cause for rejoicing (Luke 10:17, 20) and, in fact, many who say they have cast out demons in Jesus's name will be excluded from the kingdom of heaven (Matt. 7:22). Mary Magdalene is named as a person out of whom seven demons were cast—she is the only (former) demoniac named in the Bible. Paul maintains that pagan sacrifices are actually being offered to demons (1 Cor. 10:20–21; cf. Rev. 9:20, which speaks of the worship of demons). Finally, in 1 Tim. 4:1 a different class of demon is mentioned than is referenced elsewhere in the Bible: deceitful spirits who lead people to adopt the "teaching of demons" rather than the orthodox truth of the apostolic tradition. See also angel; Belial, Beliar; devil; divination; magic; Satan.


Efird, J. M., & Powell, M. A. (2011). demon. In M. A. Powell (Ed.), The HarperCollins Bible Dictionary (Revised and Updated) (Third Edition, pp. 192–193). New York: HarperCollins.

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