Jude continues to warn against departures from the faith by false teachers. He says that they speak evil of spiritual authorities, and on the fleshly plane they defile and corrupt (Jude 1:8-11).
¶“8Like [Sodom and Gomorrah] these dreamers defile the flesh, despise authority, and speak evil of glorious ones. 9Yet Michael the archangel, when contending with the devil, arguing over the body of Moses, dared not bring an evil-speaking judgment against him, but said, 'The Lord rebuke you!'. 10But these speak evil of things they don't understand, and what they understand naturally like unreasoning animals, in those things they corrupt themselves. 11Woe unto them! for they have travelled in Cain’s way; and rushed for reward to Balaam’s error; and perished in Korah’s contention” (Jude 1:8-11).
Jude is referring to those he mentioned earlier: ¶“Certain men came in by stealth, those who long ago were written down for this condemnation: ungodly men who change the grace of our God into sensuality and deny our only Master and Lord, Jesus Christ” (Jude 1:4).
Now further down, in verses 8-11, Jude says three more things about these men. Firstly they are dreamers. Secondly they defile the flesh. Thirdly they despise authority and speak evil of glorious ones.
You will recall that Jude has already said, “the faith [was] once for all delivered to the holy people” (Jude 1:3). There is no new revelation. Not even this letter from Jude reveals anything new. His letter is simply to “urge” (Jude 1:3). and to “remind” (Jude 1:5).
So someone comes in and says, "God spoke to me in a dream" and claims to have new insight and knowledge that was not revealed in “the words previously spoken by the apostles of our Lord Jesus Christ” (Jude 1:17). Jude warns us against these dreamers.
Jude says, “But these speak evil of things they don't understand, and what they understand naturally like unreasoning animals, in those things they corrupt themselves.” (Jude 1:10).
These impostors are ignorant. They don't understand the spiritual and heavenly truths they speak against. They are even ignorant about the flesh and its sensuality and sexuality. So they defile the flesh with immoral acts claiming they are the work and will of God.
The most important mark of these false men is that they despise and speak evil against heavenly authority. So they despise “the apostles of our Lord Jesus Christ” (Jude 1:17). and “the glorious ones” (Jude 1:8) —the angels who have brought visions and dreams and revelation from God (eg Revelation 1:1).
When these men speak such evil they blaspheme* because these apostles and angels are messengers of Christ. To speak evil of them is to “deny the only Lord God and our Lord Jesus Christ” who sent them (Jude 1:4).
*The Greek for “speak evil” is βλασφημια blasphemia.
Jude says, “Yet Michael the archangel, when contending with the devil, arguing over the body of Moses, dared not bring an evil-speaking judgment against him, but said, 'The Lord rebuke you!'” (Jude 1:9).
There is a lot of speculation about the origin of this account, but no proof. Jude’s account is found nowhere else in scripture, but he must have regarded it as true, and fit to show that angelic majesties contend for truth and right, but do not speak evil against wrongdoers. They let God’s word suffice.
Peter tells us the same: ¶“Angels, though greater in might and power, do not pronounce an evil-speaking judgment before the Lord...” (2Peter 2:10-12). What right, then, does anyone have to speak evil of angelic magesties?
One way to speak evil of an angel is to say, “An angel appeared to me in a dream, and told me...” and then say something not in the faith once for all delivered.
Only God’s word can tell us who genuinely saw angels and were instructed by them. Furthermore, no genuine angel would change the faith once for all delivered.
Next Jude says, Woe unto them! for they have travelled in Cain’s way; and rushed for reward to Balaam’s error; and perished in Korah’s contention” (Jude 8:11). The three examples are in the Bible as follows: