When God created spirit creatures, he made them free moral agents, able to choose for themselves whether to do good or bad. Sadly, after the creation of humankind, an undisclosed number of angels chose to do bad by rebelling against God.
The first and most infamous spirit to rebel became Satan. “He did not stand fast in the truth,” said Jesus Christ. (John 8:44) What moved Satan to turn against God? He began to covet the worship that belongs exclusively to the Creator, and then he acted on that desire by setting himself up as a rival god
In this way he made himself “Satan,” a word that means “resister.” Centuries later, prior to the Flood of Noah’s day, other angels joined Satan, forsaking their heavenly position to materialize in human form and dwell on earth. (Genesis 6:1-4; James 1:13-15) When the Flood occurred, the materialized “angels that sinned” apparently returned to the spirit realm. (2 Peter 2:4; Genesis 7:17-24) In time, they came to be called demons.—Deuteronomy 32:17; Mark 1:34.
Though evidently prevented from again materializing as humans, the demons still have great power and influence over the minds and lives of people. In fact, Satan, together with his demon hordes, is “misleading the entire inhabited earth.” (Revelation 12:9;
To a large extent, by means of the “teachings of demons.” (1 Timothy 4:1)
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