What I find much more difficult with Jude is that fact that he quotes from Jewish Apocrypha written only a couple of centuries before and claims the prophecy really was from Enoch in Genesis.
I don't believe that for one minute ---
QV please.
What don't you believe for one minute?
That Jude thought he was quoting from Enoch in the Book of Genesis?
Jude tells us so himself. Jude 1:14
It was also about these that Enoch, the seventh from Adam, prophesied, saying...
That Jude is quoting from Jewish Apocrypha?
Your QV link says he is.
The Book of Enoch is any of several pseudepigraphal (falsely attributed works, texts whose claimed authorship is unfounded) works that attribute themselves to Enoch, the great-grandfather of Noah; that is, Enoch son of Jared (Genesis 5:18). Enoch is also one of the three people in the Bible taken up to heaven while still alive (the only others being Elijah and Jesus), as the Bible says "And Enoch walked with God, and he was not; for God took him." (Genesis 5:24; see also Hebrews 11:5). Most commonly, the phrase "Book of Enoch" refers to 1 Enoch, which is wholly extant only in the Ethiopic language.
The biblical book of Jude quotes from the Book of Enoch in verses 14-15, Enoch, the seventh from Adam, prophesied about these men: See, the Lord is coming with thousands upon thousands of his holy ones to judge everyone, and to convict all the ungodly of all the ungodly acts they have done in the ungodly way, and of all the harsh words ungodly sinners have spoken against him. But this does not mean the Book of Enoch is inspired by God and should be in the Bible.
Judes quote is not the only quote in the Bible from a non-biblical source. The Apostle Paul quotes Epimenides in Titus 1:12 but that does not mean we should give any additional authority to Epimenides writings. The same is true with Jude, verse 14. Jude quoting from Enoch 1:9 does not indicate the entire book is inspired, or even true. All it means is that particular verse is true.
That is fine too, as far as it goes. As Paul said Phil 4:8
Finally, brothers, whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is commendable, if there is any excellence, if there is anything worthy of praise, think about these things. Paul found what was true and honourable in pagan poets and quoted them, how much more so should we lay hold of what is true, honourable, just and pure in Jewish religious texts. Or even Star Trek. However the problem is not Jude quoting what is true in the Apocryphal book of Enoch, it is Jude thinking and claiming in his letter that this quote from the book of Enoch was really from the Enoch in Genesis
It is interesting to note that no scholars believe the Book of Enoch to have truly been written by the Enoch in the Bible. Enoch was seven generations from Adam, prior to the Flood (Genesis 5:1-24). Evidently, though, this was genuinely something that Enoch prophesied or the Bible would not attribute it to him, Enoch, the seventh from Adam, prophesied about these men
(Jude 14). This saying of Enoch was evidently handed down by tradition, and eventually recorded in the Book of Enoch.
That's the problem there. There is no 'evidently' about it. There is no evidence of a genuine prophecy of Enoch preserved through the flood and handed down by Jewish tradition, which the author of the apocryphal Book of Enoch took and inserted in his work of fiction. It is wishful thinking. Jude quoted an apocryphal book and thought it was genuine.
We should treat the Book of Enoch (and the other books like it) in the same manner we do the other Apocryphal writings. Some of what the Apocrypha says is true and correct, but at the same time, much of it is false and historically inaccurate. If you read these books, you have to treat them as interesting but fallible historical documents, not as the inspired, authoritative Word of God.