All the spirit persons that Jehovah created were good. Then one angel turned bad. He is Satan the Devil. Satan wanted people on earth to worship him instead of Jehovah. This is what happened:

In the garden of Eden, there were many trees that bore delicious fruit. Jehovah told Adam and his wife, Eve, that they could freely eat from them. But there was one tree that God said they should not eat from. He said that if they ate from it, they would positively die.—Genesis 2:9, 16, 17.

One day Eve was by herself when a snake spoke to her. Of course, it was not really the snake that talked; it was Satan the Devil who made it seem as if the snake were talking. Satan told Eve that if she ate from the forbidden fruit, she would be wise like God. He also said that she would not die. Both these statements were lies. Nevertheless, Eve believed Satan and ate the fruit. Later, she gave some to Adam, and he ate too.—Genesis 3:1-6.

From this true story, we learn that Satan is a rebel and a liar. He told Eve that if she disobeyed God, she would not die. That was a lie. She did die and so did Adam. Satan did not die then, although he will eventually because he sinned. Meantime, however, he is alive and continues to mislead mankind. He is still a liar, and he tries to get people to break God’s laws.—John 8:44.

Later, other angels turned bad. These angels noticed the good-looking women on earth and wanted to have sexual relations with them. So they came to the earth and put on male human bodies. Then they took the women for themselves. This was against God’s purpose.—Genesis 6:1, 2; Jude 6.

It also caused much trouble for mankind. The wives of these angels bore children, but they were not normal children. They grew to be violent and cruel giants. Eventually the earth became so filled with violence that Jehovah decided to destroy the wicked people by a great flood. The only humans who survived the Flood were righteous Noah and his family.—Genesis 6:4, 11; 7:23.

The wicked angels, however, returned to the spirit realm; they did not die. But they were punished. They were not allowed back into God’s family of righteous angels. Furthermore, Jehovah no longer allowed them to put on human bodies. And eventually they will die in the great judgment.—2 Peter 2:4; Jude 6.

In the early part of our century, there was a war in heaven. The Bible book of Revelation describes what happened: “And war broke out in heaven: Michael [the resurrected Jesus Christ] and his [good] angels battled with the dragon [Satan], and the dragon and its [bad] angels battled but it did not prevail, neither was a place found for them any longer in heaven. So down the great dragon was hurled, the original serpent, the one called Devil and Satan, who is misleading the entire inhabited earth; he was hurled down to the earth, and his [bad] angels were hurled down with him.”

What was the result? The account continues: “On this account be glad, you heavens and you who reside in them!” The good angels could be glad because Satan and the bad angels, or spirits, were no longer in heaven. But what about people on earth? The Bible says: “Woe for the earth and for the sea, because the Devil has come down to you, having great anger, knowing he has a short period of time.”—Revelation 12:7-9, 12.

Yes, Satan and his wicked companions mislead and cause great woe for people on earth. These wicked angels are called demons. They are enemies of God. All of them are evil.