Revelation 9:11

They had a king over them who was the angel of the deep pit [See verses 1-2]. His name in Hebrew was "Abaddon," and in Greek it was "Apollyon" [Note: These words both mean "Destroyer"].

Ephesians 2:2

You practiced such things when you lived according to the evil ways of this world, and according to the ruler of the [spiritual] powers of the air. [Note: This refers to Satan, whose influence permeates life around us]. He is the [evil] spirit who is now at work in people who are disobedient [to God].

John 8:44

You belong to your father the devil, and you are [always] wanting to do what your father desires. He was a murderer from the [very] beginning [Note: This is probably a reference to Satan's influence on Adam, Eve and Cain in the Garden of Eden] and does not stand for the truth, because there is no truth in him. When he lies, he only speaks what is part of his nature, because he is a liar and the father of [all] liars.

John 12:31

Judgment is now coming to this world; the prince of this world [i.e., Satan] will now be driven out.

John 14:30

I will not speak with you very much anymore because the ruler of the world [i.e., Satan] is coming, and he has no control over me.

John 16:11

[And it will be shown] judgment, because the ruler of this world [i.e., Satan. See 12:31] has been condemned [i.e., by Jesus' death and resurrection].

2 Corinthians 4:4

For the god of this world [i.e., Satan] has blinded the minds of the unbelievers, so that they would not see the light of the Gospel of the splendor of Christ, who is the image of God.

1 John 4:4

[But], you people are [followers] of God, little children [i.e., dear ones], and you have overcome them [i.e., these false teachers] because He who is in your lives [i.e., the Holy Spirit, See 3:24] is greater [i.e., more powerful] than he who is in [i.e., dominates] the world [i.e., Satan. See II Cor. 4:4].

1 John 5:19

We [also] know that we are [children] of God and that the people of the whole world lie under [the control of] the evil one [i.e., Satan].

Revelation 9:1-2

[When] the fifth angel sounded its trumpet, I saw a star that had fallen from the sky to the earth. And the key to the shaft leading to the deep pit [Note: This is thought to be the place where the devil and his demons live] was given to him.

Revelation 12:9

Then the great dragon was thrown out [of heaven]; he is the snake from ancient times who is [also] called "the Devil," and "Satan," the deceiver of the entire world. He was thrown down to earth along with his angels.

Treasury of Scripture Knowledge

Summary

And they had a king over them, which is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue hath his name Apollyon.

The angel

Abaddon

Bible References

They had

Revelation 12:9
Then the great dragon was thrown out [of heaven]; he is the snake from ancient times who is [also] called "the Devil," and "Satan," the deceiver of the entire world. He was thrown down to earth along with his angels.
John 12:31
Judgment is now coming to this world; the prince of this world [i.e., Satan] will now be driven out.
John 14:30
I will not speak with you very much anymore because the ruler of the world [i.e., Satan] is coming, and he has no control over me.
John 16:11
[And it will be shown] judgment, because the ruler of this world [i.e., Satan. See 12:31] has been condemned [i.e., by Jesus' death and resurrection].
2 Corinthians 4:4
For the god of this world [i.e., Satan] has blinded the minds of the unbelievers, so that they would not see the light of the Gospel of the splendor of Christ, who is the image of God.
Ephesians 2:2
You practiced such things when you lived according to the evil ways of this world, and according to the ruler of the [spiritual] powers of the air. [Note: This refers to Satan, whose influence permeates life around us]. He is the [evil] spirit who is now at work in people who are disobedient [to God].
1 John 4:4
[But], you people are [followers] of God, little children [i.e., dear ones], and you have overcome them [i.e., these false teachers] because He who is in your lives [i.e., the Holy Spirit, See 3:24] is greater [i.e., more powerful] than he who is in [i.e., dominates] the world [i.e., Satan. See II Cor. 4:4].
1 John 5:19
We [also] know that we are [children] of God and that the people of the whole world lie under [the control of] the evil one [i.e., Satan].

The angel

Revelation 9:1
[When] the fifth angel sounded its trumpet, I saw a star that had fallen from the sky to the earth. And the key to the shaft leading to the deep pit [Note: This is thought to be the place where the devil and his demons live] was given to him.

Abaddon

John 8:44
You belong to your father the devil, and you are [always] wanting to do what your father desires. He was a murderer from the [very] beginning [Note: This is probably a reference to Satan's influence on Adam, Eve and Cain in the Garden of Eden] and does not stand for the truth, because there is no truth in him. When he lies, he only speaks what is part of his nature, because he is a liar and the father of [all] liars.