Jude warns his readers by describing the polluting influence of the “certain men” on the Church’s holy feasts, their self-serving nature, their empty promises, their hypocritical lives, their shameful lifestyle, and most importantly, their dire destiny. The consequential descriptions of all of these are twice dead and for whom blackest darkness has been reserved forever. It seems that Jude is maxing out the “fear-threat” approach to reach the infiltrators—and anyone who is even remotely impressed or persuaded by them.
Jude 1:14-16 NTBDC: Why is Jude here quoting from the uninspired Book of Enoch as though it were Inspired?
The book of Enoch is non-Biblical and pseudepigraphical (what we have today is not written by Enoch). The oldest portions of the text are estimated to date from about 300 B.C.E. The book of Jude was penned by Jesus’ half-brother some 365 years later in about 65 C.E., written in Palestine.