It is no big secret that the author of Jude quotes the non-canonical work of 1 Enoch – specifically, 1 En. 1.9 in Jude 14-15 (this quotation is taken from the Book of Watchers which constitutes chapters of 1-36 of 1 Enoch). When one takes into consideration how Jude places the quotation of 1 Enoch 1.9 in between references to the Hebrew Bible (vv. 5-7,11) and the authoritative voice of the Apostles (vv. 17-18), it is no surprise that most commentators agree that the author of Jude viewed 1 Enoch as authoritative Scripture. For instance, Walter Dunnett says that considering how Jude introduces the quotation in vv. 14-15 he “clearly accepted it as inspired, apparently historical, and true utterance,” though adding the caveat that Jude was not “necessarily placing approval on the entire content of the Book of Enoch.”
1 Enoch is very important for the author of Jude. Richard Bauckham states that “1 Enoch 1-5 and related passages in the Enochic literature lie at the foundation of Jude’s exegetical work.”  There are two references to 1 Enoch that are quite apparent in Jude. The first is the explicit citation of the theophany of 1 En. 1.9 in Jude 14-15, a quotation which Carroll Osburn notes “must certainly be numbered among the most neglected passages in New Testament exegesis.”  Interestingly, none of the extant Greek, Aramaic, and Ethiopic manuscripts of 1 Enoch contain a stated subject in 1 En. 1.9. Instead, the subject of the theophany is found in the antecedents “the Great Holy One” (1 En. 1.3) and “the eternal God” (1 En. 1.4). In quoting 1 En. 1.9 Jude provides the subject of κυριος, a designation of Jesus throughout the epistle (see vv. 4, 14, 21, 25), and in doing so he is contemporizing the text of 1 Enoch for his audience.
A second indubitable reference to 1 Enoch is found in the angels who sinned of Jude 6. While the ultimate source of this tradition can be traced back to the cryptic account given in Gen. 6.4, Jude’s account is undoubtedly more indebted to 1 En. 6-19. This Enochic literature presents the origin and escalation of evil as being attributable to certain angels (called “Watchers”) who, having left the heavens, descended to the earth, and after procuring women for themselves, produced offspring to which they passed along forbidden knowledge. This theme is picked up in Jude 6 which states that the angels “did not stay within their own position of authority, but left their proper dwelling.” Compare this to the following passage from 1 Enoch:
Enoch, righteous scribe, go and say to the watchers of heaven – who forsook the highest heaven, the sanctuary of their eternal station, and defiled themselves with women” (1 En. 12.4).
Other words and phrases Jude uses in regards to the angels – “great day of judgment”, “darkness”, “binding” – are also found in 1 Enoch (10.4, 6, 12). The angels of Jude 6 are also linked in v. 7 with 1 Enoch when Jude states that the inhabitants of Sodom and Gomorrah “likewise indulged in sexual immorality and pursued unnatural desire” (Gk: σαρκος ετερας, “strange flesh”). In other words, the inhabitants of Sodom and Gomorrah likewise pursued strange flesh (in attempting to sexually assault the angels in Gen. 16) just as the angels mentioned in Jude 6 pursued the strange flesh of human women. As with Jude 14-15, the allusion to 1 Enoch in Jude 6 serves as a polemic against Jude’s own opponents who apparently are proponents of some sort of libertine anti-nominism. Again, Jude is found to be contemporizing the text of 1 Enoch.
Apart from these two instances, there are also other possible allusions in the epistle. The introduction of Jude contains an important parallel in 1 Enoch.
τοῖς ἐν θεῷ πατρὶ ἠγαπημένοις καὶ Ἰησοῦ Χριστῷ τετηρημένοις κλητοῖς· ἔλεος ὑμῖν καὶ εἰρήνη καὶ ἀγάπη πληθυνθείη (Jude 1-2)
To those who are called, beloved in God the Father and kept for Jesus Christ. May mercy, peace, and love be multiplied to you.
While 1 Enoch 1.8 says:
καὶ μετὰ τῶν δικαίων τὴν εἰρήνην ποιήσει, καὶ ἐπὶ τοὺς ἐκλεκτοὺς ἔσται συντήρησις καὶ εἰρήνη, καὶ ἐπ’ αὐτοὺς γενήσεται ἔλεος.
With the righteous he will make peace, and over the chosen there will be protection, and upon them will be mercy.
Both Jude vv. 1-2 and 1 En. 1.8 pronounce a blessing of “peace” and “mercy” on the “chosen/called”, while also noting that they will be and “protected/kept”. This is indicative that Jude is reading 1 Enoch in such a manner that he sees the “chosen/elect” and the “ungodly” of 1 Enoch 1 as being fulfilled in the “chosen/elect” recipients of his own epistle and the “ungodly” opponents.
Possibly confirming this is Jude 4 which says that “certain persons have crept in unnoticed, those who were long beforehand marked out for this condemnation.” Commentators have variously speculated to what the “long beforehand” refers to, with candidates being the Old Testament, the Apostles, or even 2 Peter (assuming it was written prior to Jude which is quite a minority view in scholarship). It is quite possible that the author actually had in mind 1 Enoch 1.2 which states: “Not for this generation do I expound, but concerning one that is distant I speak.” Is this what the author of Jude is referring to in verse 4? I consider it quite possible.
Another possible allusion to 1 Enoch has been proposed by Osburn. While not the focus of his article, Osburn briefly notes the connection between 1 En. 67.10 and Jude 4, the former of which says: “For judgment will come upon them because they believe in the lust of their flesh, but they deny the spirit of the Lord.” Compare that with Jude v. 4 which says that the ασεβεις are those who “pervert the grace of our God into sensuality and deny our only Master and Lord, Jesus Christ.” Osburn notes that while this isn’t a direct quotation, it is “an adaptation” of the verse which adjusts the wording in light of “Jude’s historical concern and theological understanding,” which is to say that Jude modifies the text in light of his newfound Christological understanding of God and Scripture. Additionally, Dunnett mentions a possible connection between Jude 4 with the following: “For they have denied the Lord of Spirits and his Anointed One” (1 En. 48.10).
The current view of Parables dates it to the early first-century CE and gives it a Jewish origin (as opposed to a Christian one). James Charlesworth, for instance, dates Parables to the time of Herod the Great and the Herodians. While this does allow the possibility that Parables was indeed known to a Christian writing in late first-century Palestine, I think that trying to make a connection between Jude 4 and 1 Enoch 48.10 or 67.4 is quite possibly forcing a connection that isn’t really there; the connection between Jude and 1 Enoch in these instances is simply not as clear and strong as that found between Jude 1-2 and 1 En. 1.8 or Jude 4 and 1 En. 6-19.
As seen through a look at Jude’s adaptation of 1 Enoch, the epistle demonstrates an exegesis similar to that found in the Qumran pesharim. The way in which Jude interprets the Old Testament texts, as well as 1 Enoch, would be very much at home amongst the Qumran exegetes. Just as he Qumran community saw sacred scripture being fulfilled in their own day and community, and Jude reads 1 Enoch in a similar manner, seeing the “chosen/elect” and “ungodly” of 1 Enoch as being fulfilled in the “chosen/elect” recipients of his own epistle and in his “ungodly” opponents, demonstrating that the author of Jude saw the eschatological salvation and judgment in 1 Enoch as being fulfilled in his own time.
 On the certainty that Jude is quoting from 1 Enoch, see Carroll D. Osburn, ‘The Christological Use of 1 Enoch i.9 in Jude 14, 15’, New Testament Studies 23 (1977): 334-341.
 Walter M. Dunnett, ‘The Hermeneutics of Jude and 2 Peter: The Use of Ancient Jewish Traditions’, Journal of the Evangelical Society 31 (1988): 287-92. Quote from pg. 289.
 Richard J. Bauckham, Jude and the Relatives of Jesus in the Early Church (Edinburgh, Scotland: T&T Clark, 1990), 226.
 Osburn, ‘The Christological Use of 1 Enoch i.9 in Jude 14, 15’, 334. See Bauckham, Jude and the Relatives, 288-302 for an in-depth examination of Jude’s quotation of 1 En. 1.9.
 Most commentators seem to be in agreement that the Epistle of Jude is drawing from 1 Enoch in v. 6, e.g. Thomas Wolthius, Jude and Jewish Tradition, Calvin Theological Journal 221 (1987): 21-41 (esp. pp. 24-37); Walter M. Dunnett, ‘The Hermeneutics of Jude and 2 Peter: The Use of Ancient Jewish Traditions’, (Journal of the Evangelical Society 31, 1988: 287-92), 288; Richard J. Bauckham, 2 Peter, Jude, (Waco, TX: Word Books, 1983), 50-53; idem, Jude and the Relatives, 226; J.D. Charles, Literary Strategy in the Epistle of Jude (Scranton, PA: University of Scranton Press, 1993), 108-16 and 145-49; idem, ‘The Angels Under Reserve in 2 Peter and Jude’ (Bulletin for Biblical Research 15.1 2005: 39-48), 45-48.
 Translations of 1 Enoch are taken from George W.E. Nickelsburg and James C. VanderKam, 1 Enoch: A New Translation. Minneapolis, MN: Augsburg Fortress, 2004.
 For further explication upon this point see Bauckham, Jude and the Relatives, 162-68.
 See Charles, Literary Strategy, 153-62 for a fuller discussion of Enochic tradition-material in Jude.
 Greek text taken from Matthew Black, Pseudepigrapha veteris testament Graece, 3 (Leiden: Brill, 1970), 19-20.
 In his great commentary, 1 Enoch 1: A Commentary on the Book of 1 Enoch, Chapters 1-36; 81-108 (Hermeneia; Minneapolis, MN: Augsburg Fortress, 2001), Nickelsburg states that the addition of the second occurrence of καὶ εἰρήνη in the Greek is “doubtless an addition from the previous line” (pg. 143), and thus excises it from his translation.
 Joseph B. Mayor, The Epistles of St. Jude and II Peter: Greek Text with Introduction, Notes, and Comments (New York, NY: Macmillan, 1907), 76-77 notices the connection between 1 En. 1.8 and Jude 2, though surprisingly Bauckham and Charles do not seem to.
 For a succinct overview of this question, see Peter H. Davids, The Letters of 2 Peter and Jude (Pillar New Testament Commentary; Grand Rapids, MI: Eerdmans, 2006), 43-44.
 Carroll D. Osburn, ‘1 Enoch 80:2 (67:5-7) and Jude 12-13’, Catholic Biblical Quarterly 47 (1985): 296-303.
 Ibid, 300.
 Dunnett, The Hermeneutics of Jude and 2 Peter, 288-89.
 For a very recent discussion of the Parables of Enoch see Parables of Enoch: A Paradigm Shift, ed’s Darrell Bock and James Charlesworth, Bloomsbury T&T Clark, 2013. See in particular the essay by James H. Charlesworth, The Date and Provenience of the Parables of Enoch, pp. 37-57.