With regard to Enoch falling out of favor, I pulled the following excerpt from this link a few years back:
The theme of the Book of Enoch dealing with the nature and deeds of the fallen angels so infuriated the later Church fathers that one, Filastrius, actually condemned it openly as heresy (Filastrius, Liber de Haeresibus, no. 108). Nor did the rabbis deign to give credence to the book’s teaching about angels. Rabbi Simeon ben Jochai in the second century A.D. pronounced a curse upon those who believed it (Delitzsch, p. 223).
So the book was denounced, banned, cursed, no doubt burned and shredded–and last but not least, lost (and conveniently forgotten) for a thousand years. But with an uncanny persistence, the Book of Enoch found its way back into circulation two centuries ago.
In 1773, rumors of a surviving copy of the book drew Scottish explorer James Bruce to distant Ethiopia. True to hearsay, the Book of Enoch had been preserved by the Ethiopic church, which put it right alongside the other books of the Bible…
Though it was once believed to be post-Christian (the similarities to Christian terminology and teaching are striking), recent discoveries of copies of the book among the Dead Sea Scrolls found at Qumran prove that the book was in existence before the time of Jesus Christ. But the date of the original writing upon which the second century B.C. Qumran copies were based is shrouded in obscurity. It is, in a word, old…
There is abundant proof that Christ approved of the Book of Enoch. Over a hundred phrases in the New Testament find precedents in the Book of Enoch.
Another remarkable bit of evidence for the early Christians’ acceptance of the Book of Enoch was for many years buried under the King James Bible’s mistranslation of Luke 9:35, describing the transfiguration of Christ: "And there came a voice out of the cloud, saying, ‘This is my beloved Son: hear him." Apparently the translator here wished to make this verse agree with a similar verse in Matthew and Mark. But Luke’s verse in the original Greek reads: "This is my Son, the Elect One (from the Greek ho eklelegmenos, lit., "the elect one"): hear him."
The "Elect One" is a most significant term (found fourteen times) in the Book of Enoch. If the book was indeed known to the apostles of Christ, with its abundant descriptions of the Elect One who should "sit upon the throne of glory" and the Elect One who should "dwell in the midst of them," then the great scriptural authenticity is accorded to the Book of Enoch when the "voice out of the cloud" tells the apostles, "This is my Son, the Elect One"–the one promised in the Book of Enoch.
The Book of Jude tells us in vs. 14 that "Enoch, the seventh from Adam, prophesied…" Jude also, in vs. 15, makes a direct reference to the Book of Enoch (2:1), where he writes, "to execute judgment on all, to convict all who are ungodly…" …
Many of the early church fathers also supported the Enochian writings. Justin Martyr ascribed all evil to demons whom he alleged to be the offspring of the angels who fell through lust for women (from the Ibid.)–directly referencing the Enochian writings.
Athenagoras, writing in his work called Legatio in about 170 A.D., regards Enoch as a true prophet. He describes the angels which "violated both their own nature and their office." In his writings, he goes into detail about the nature of fallen angels and the cause of their fall, which comes directly from the Enochian writings.
Many other church fathers: Tatian (110-172); Irenaeus, Bishop of Lyons (115-185); Clement of Alexandria (150-220); Tertullian (160-230); Origen (186-255); Lactantius (260-330); in addition to: Methodius of Philippi, Minucius Felix, Commodianus, and Ambrose of Milanalso–also approved of and supported the Enochian writings…
One by one the arguments against the Book of Enoch fade away. The day may soon arrive when the final complaints about the Book of Enoch’s lack of historicity and "late date" are also silenced by new evidence of the book’s real antiquity.