A furious twenty-five-verse denunciation that quotes, by name and as prophecy, a book that is not in the Bible. That citation is the most interesting fact about it and the reason it was argued over for centuries.
What the book is
Jude is a single sustained attack on people who have entered the community and are, in the writer’s account, exploiting it. It piles up examples of judgement — the wilderness generation, the fallen angels, Sodom, Cain, Balaam, Korah — and closes with a well-known doxology.
The writer identifies himself as Jude, brother of James, which points to the family of Jesus.
How it is put together
The letter is a chain of examples rather than an argument. It is dense with allusion and assumes a readership that will recognise every reference without explanation, which is itself evidence about its intended audience.
Verses 4 to 18 run parallel to 2 Peter 2. The majority position is that 2 Peter used Jude rather than the reverse, largely because 2 Peter removes exactly the material that later became awkward.
The quotation from Enoch
Verses 14 and 15 quote a prophecy about the Lord coming with his holy myriads to execute judgement, and attribute it to Enoch, the seventh from Adam. The quotation corresponds closely to a passage in the opening chapter of 1 Enoch, a Jewish apocalyptic work of the third to first centuries BCE that is not part of the Jewish or most Christian canons.
This is not an allusion but a citation, introduced with a formula of prophecy. Verse 9, on the dispute over the body of Moses, is generally taken to depend on the Assumption of Moses, another work outside the canon.
The consequence was that Jude’s own canonical status was questioned in antiquity precisely on this ground — Eusebius lists it among the disputed books — and later Christian writers were uncomfortable with it.
What it demonstrates is straightforward and important: the boundaries of scripture were not fixed when the New Testament was being written, and a writer who was later canonised could treat as prophecy a book that was later excluded. Any argument that assumes a stable canon in the first century has to reckon with these twenty-five verses.
The dating question
If the attribution holds, the letter belongs to the first century and could be relatively early. Against the attribution: the Greek is competent and rhetorically constructed, the letter refers to the faith once delivered as an established deposit, and it speaks of the apostles’ predictions as something in the past.
Proposals range from the fifties to the early second century, and there is no external anchor. The dependence relationship with 2 Peter gives a relative ordering but not an absolute date.
Where the external record touches it
1 Enoch itself is the substantive external material, and it is unusually well documented. Aramaic fragments of it were found at Qumran, establishing that it circulated in Judaea before the turn of the era; the complete text survives in Ge’ez, preserved in the Ethiopian church, where it remains canonical.
That means Jude’s source can be read, dated in part, and compared — which is exactly the kind of check this site exists to perform, and here it comes out clean: the quotation is real, the source is identifiable, and the citation formula is what it appears to be.
Related: 2 Peter, which reuses much of this letter, and the method note on the five source layers.