ANSWER: First, we need to know where we get the word angel in our Bible. In the Old Testament, the original Hebrew commonly used is malak (Strong's Concordance #H4397), which literally means a messenger 98 times, angel 111 times, and ambassador some 4 times. In the New Testament, the Greek word from which we get the English word angel is angelos (Strong's Concordance #G32), which literally means messenger and envoy.
Angelic responsibilities include bringing messages from one part of the universe to the other to God the Father and his Son Jesus the Christ and to execute their will. Matthew 18:10, in discussing the elect, especially the newly baptized elect whom Jesus calls "one of these little ones" or a small innocent child not yet baptized, says that their angels can view the face of God. This implies that one of their tasks is to look after each one of us who have been called and baptized as well as little children.
Some have contended that spirit beings are not able to die. This might be conjecture as there are no verses in the Bible that state such. The angel's body at the present time is made up of a spiritual substance. They were created beings and have been given the ability to choose to obey or not the Law of God and His voice.
You were the seal of perfection, full of wisdom and perfect in beauty.
The devil is being discussed in these verses because he was the one who walked in the midst of the stones of fire at the throne of God on his holy mountain. Verses 18 and 19 of the same chapter states that God will make the devil into ashes and that he will be no more.
. . . And I turned you to ashes upon the earth, in the sight of all who saw you. All who knew you among the peoples are astonished at you. You have become a horror, and shall be NO MORE forever. (Ezekiel 28:18 - 19)
This certainly is a strong indication that the devil can be put to a final death (destroyed) even though he is made of spirit.
Ezekiel 18:20 says that the soul that sins shall die. If this word soul would be translated as LIFE FORCE then it might be speaking to the angel realm as well as the human realm. Only God can prevent humans from being resurrected into a new body containing that human's life force and only God can remove the life force from the angelic hosts.
Satan convinced one-third of all the angelic beings to follow his rebellion (Revelation 12:3 - 4). Most of the rebellious spirits, now called demons or devils, have been incarcerated in a bottomless pit until such time that the Father will permit their release for their judgment.
6. And the angels who did not keep their own original domain (the KJV has 'first estate' while the NKJV has 'proper domain'), but deserted their habitation, He is holding in eternal bonds (some translations have 'chains') under darkness unto the judgment of the great day (judgment day). (Jude 6)
I can find no verse in the Bible that says evil, unrepentant spirit beings will be in torment or tortured forever.
The Bible tells us emphatically that when the elect have been raised into their spiritual bodies at the first resurrection, they will not only help judge the world but also spirit beings. This is what Paul told the church at Corinth.
Dare any of you, having a matter against another, go to law before the unrighteous, and not before the saints? Do you not know that the saints will JUDGE the world? And if the world will be judged by you, are you unworthy to judge the smallest matters? Do you not know that WE SHALL JUDGE ANGELS? . . . (1Corinthians 6:1 - 4)
Surprising though it may seem, the angels look forward to the day when the elected saints will teach them the deep things of God. Peter tells us that they want to understand these things but they do not even understand why they are doing what they are doing (1Peter 1:10 - 12).
Angelic beings were not promised to rule the world to come or to be sons of God.
"For He has NOT put the world to come, of which we speak, in subjection to angels. But one testified in a certain place, saying: 'What is MAN that You are mindful of him . . . ' " (Hebrews 2:5 - 6)
There will come a day when even angels will be judged to see if they have obeyed the laws of God, especially the Ten Commandments. Why do they need to be judged? Because at least one third of them have sinned and deserve death. Who will do this judging? Based on your Bible, it is those humans who have entered into the Kingdom as spirit born children of God.