Jude tells us in Jude 1:8 that the men who have crept into the Church secretly (viz. the spies of Jude 1:4) are dreamers (enupniazomai; G1797), or men who fancied themselves to be prophets. The word is used in only one other place in the New Covenant text, Acts 2:17. There Peter is speaking and he said what the Jewish onlookers saw in the aftermath of the Holy Spirit falling upon the disciples of Jesus was the fulfillment of Joel’s prophecy, which claimed that at the end of the age the Lord would pour out his Spirit upon men and (among other things) old men would dream (G1797) dreams (G1798).
The same Greek word is used for the dreams of the prophets, both good and bad, in the Septuagint, which is the Greek version of the Old Covenant text. It is used of Jacob (Genesis 28:12), Joseph in several verses of Genesis chapter 37, of Gideon (Judges 7:13) and others. It is also used of evil men:
I heard what the prophets speak who prophesy lies by my name, saying, I dreamed (G1797) a dream (G1798). For how long shall it be in the heart of the prophets prophesying lies, and in their prophesying the desires of their heart? The ones devising ways to forget my name by their dreams, which each was described to his neighbor; as their fathers forgot my name in service to Baal. (Jeremiah 23:25-27; parenthesis mine)
It seems that in verse-8 Jude is offering his readers a recap of the three examples of the folks who were judged by the Lord in Jude 1:5-7, but he mentions them in reverse order in verse-8. That is, the Sodomites were those who defile the flesh; the patriarchs were examples of those who despise dominion, and the unbelievers who were brought out of the bondage of Egypt were examples of those who speak evil of dignities. Once again, of course, many, but not all, of the commentaries miss the mark here, because they can’t find their way out of the false doctrine that Jude was holding up angels (spirit beings) as examples of those who sinned in Genesis 6, and saying the angels are meant for the dignities whose high authoritative office was being abused by the false teachers of Jude’s day.
Nowhere in the Bible does it ever claim that an angel is a ruler of any kind. The fact of the matter is, the reverse is implied. It is men who are given rulership (Genesis 1:26; Psalm 8:4-8), but angels were created as ministering spirits who serve the needs of men who would be the heirs of salvation (Hebrews 1:14). The Throne of God is a metaphor for his authority as Ruler of all he created, but the text tells us that he never once offered a place on his Throne to an angel (Hebrews 1:13). Jesus sits there (Matthew 26:64; Acts 2:32-36), but not angels. Every position of authority that is enjoyed by men, whether he is just or unjust, derives its authority from the Throne of God, upon which the text never tells us an angelic being sits or enjoys power or authority derived from there. Nevertheless, those who are created in Christ are specifically said be seated with him at the right hand of God (Ephesians 1:20; 2:6). It is only in knowing and understanding this that we can accurately interpret the rest of the verse.
The men of Sodom abused anyone who was a stranger who was passing through their land. No one was safe anywhere or in any city of the Jordan plain. Their sin was more than sexual in nature. It was one of violence and dominance. They defiled the flesh or the body of the stranger. In the same manner, but spiritually speaking, the false teachers defiled the flesh, meaning the Church, the Body of Christ (1Corinthians 12:27; cp. 1Corinthians 3:17). While it is Christ who had placed men in authority over his Church (1Corinthians 12:28), speaking evil of these dignities and assuming they, i.e. the evil teachers (cp. 3John 1:9-10), could replace them, they defiled the Body of Christ.
Moreover, just as the antediluvian patriarchs despised the rulership of the Lord and his command to remain in the image in which they were created (Genesis 1:27), these men despised all rule and authority that wasn’t theirs. They refused to acknowledge God in what they did (Romans 1:21-22, 28), and as a result they had forgotten, ignoring by default, the prime directive of remaining in the image of God, which in reality translates to loving one’s brethren / fellow man, being free and allowing everyone else to be free, as well.
Finally, Jude warned the brethren about speaking evil of their leaders who had been appointed by God. Even unjust men rule and hold powerful offices, which derive their high authority from the authority of God, and even they must be respected for their authority’s sake (Romans 13:1; Titus 3:2). Nevertheless, just as Moses, Aaron, Caleb and Joshua were renounced by the people in favor of the ten leaders who brought back an evil report of the Promised Land, the false teachers of the first century AD slandered not only Christ, but also those he appointed as his witnesses Peter, Paul and the other leaders of the Church. No matter where they went in the Roman Empire, the Gospel had been slandered (Acts 28:22), and they were persecuted from city to city (Matthew 23:31-36; cp. Psalm 105:15), until there was no place to which they could flee for safety.