Angels of heaven do not sin or rebel against God because they possess the divine nature.
This is the promise held out to those who believe and obey the gospel.
2 Peter 1:4 by which have been given to us exceedingly great and precious promises, that through these you may be partakers of the divine nature, having escaped the corruption that is in the world through lust.
This will make us equal to the angels
Luke 20:36 "nor can they die anymore, for they are equal to the angels and are sons of God, being sons of the resurrection.
If angels can sin and die, we will be no better off than we are now and the promise of eternal life is a sham.
God’s will is done perfectly in heaven – hence the Lord’s prayer:
Matthew 6:10 Your kingdom come. Your will be done On earth as it is in heaven.
Sons of God who married the daughters of men
Angels do not marry or reproduce.
Matthew 22:30 "For in the resurrection they neither marry nor are given in marriage, but are like angels of God in heaven.
In Genesis the ‘sons of God’ who married the daughters of men refers to the sons of Seth who called upon the name of the Lord, marrying the daughters of Cain.
Genesis 4:26 And as for Seth, to him also a son was born; and he named him Enosh. Then men began to call on the name of the LORD.
In calling on the name of the Lord, they were led by the Spirit of God and are therefore referred to as ‘the sons of God’.
Romans 8:14 For as many as are led by the Spirit of God, they are the sons of God.
Genesis 6:2 that the sons of God saw the daughters of men, that they were beautiful; and they took wives for themselves of all whom they chose.
Genesis 6:4 ¶ There were giants on the earth in those days, and also afterward, when the sons of God came in to the daughters of men and they bore children to them. Those were the mighty men who were of old, men of renown.
Angels who did not keep their proper domain
Jude 1:6 And the angels who did not keep their proper domain, but left their own abode, He has reserved in everlasting chains under darkness for the judgment of the great day;
This refers to the rebellion of Korah Dathan and Abiram
Numbers 16:1 ¶ Now Korah the son of Izhar, the son of Kohath, the son of Levi, with Dathan and Abiram the sons of Eliab, and On the son of Peleth, sons of Reuben, took men; 2 and they rose up before Moses with some of the children of Israel, two hundred and fifty leaders of the congregation, representatives of the congregation, men of renown. 3 They gathered together against Moses and Aaron, and said to them, "You take too much upon yourselves, for all the congregation is holy, every one of them, and the LORD is among them. Why then do you exalt yourselves above the assembly of the LORD?"
They were ‘angels’ in the sense that they were important persons in the congregation of Israel.
They were punished by the earth opening and swallowing them deep into the earth.
Numbers 16:32 and the earth opened its mouth and swallowed them up, with their households and all the men with Korah, with all their goods.
They remain dead in the earth until the day of resurrection and judgment.
Hence we read:
They are ‘reserved in everlasting chains under darkness for the judgment of the great day;
The war in heaven
Revelation 12:7 And war broke out in heaven: Michael and his angels fought with the dragon; and the dragon and his angels fought, 8 but they did not prevail, nor was a place found for them in heaven any longer. 9 So the great dragon was cast out, that serpent of old, called the Devil and Satan, who deceives the whole world; he was cast to the earth, and his angels were cast out with him.
Revelation is a book of symbols
There can be no literal woman giving birth in heaven nor a literal dragon waiting to devour her son.
The war in heaven describes the ‘war’ in the political heavens of the Roman Empire between the Roman authorities and those who preached the gospel. The latter won the battle in the 4th century AD when Christianity was made the official religion of the Roman Empire and pagan idolatry was outlawed.
Michael and his angels represent those who preached the gospel and the dragon and his angels represents the Roman government.
So we read of the victory of the Christians:
Revelation 12:11 "And they overcame him by the blood of the Lamb and by the word of their testimony, and they did not love their lives to the death.
In conclusion - angels of God do the will of God perfectly, there is no rebellion or war in heaven. There are no ‘fallen angels’.
Satan and the devil are personifications of the proclivity to sin within man both individually and collectively.
I hope you find this helpful.
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