The pertinent problem with the book of Enoch is that it includes obvious and serious doctrinal heresies that are diametrically opposed to those of canonical Scripture.
There’s nothing heretical in 1 Enoch if one reads it according to the Alexandrian hermeneutic. It is part of the canon of the Ethiopian Tewahedo Orthodox Church and the Eritrean Tewahedo Orthodox Church, which are two of the most devout and most persecuted Christian churches on the world. They are Oriental Orthodox, and were part of the Coptic Orthodox Church (which does not regard 1 Enoch as canonical, but always allowed the Ethiopians (and Eritreans, who recently became independent of Ethiopia and their church was granted autocephalous status by Alexandria) to read it as canonical, for various good reasons - the doctrine of the Ethiopian Church is the same as the Coptic Orthodox Church (and the Syriac Orthodox Church and Armenian Apostolic Church, which are in full communion with the Coptic Orthodox Church, and whose large communities in Syria are among the most critically persecuted and endangered Christians right now, and indeed have been for the past 12 years).
Additionally St. Jude the Apostle appears to quote 1 Enoch in his epistle. I don’t know that our Lord quotes it, but St. Jude does.
Lastly, the “Gospel of Thomas”, which is a slightly corrupt list of sayings showing some Gnostic tampering, was never included in the canon by any Orthodox, Catholic or mainstream Protestant church - there is only one New Testament canon. However most of the sayings in it correspond with those sayings of our Lord in the three Synoptic Gospels, suggesting it could be a Coptic translation of a Gnostic corruption of a sayings document of our Lord, one probably used in Syria (based on the specific nature of the corrupted passages, which show a link to Syrian Gnostic doctrines taught by the likes of the Ophites and Bardesanes and by Tatian and Severian), which was evangelized by St. Thomas the Apostle, who was the subject of other Gnostic apocrypha in that region such as the “Acts of Thomas” which are interesting as historic evidence of early Christian worship but are less likely to be derived from anything legitimate, and the entirely blasphemous “Infancy Gospel of Thomas” which was I believe the book referred to by an early Church Father as being written by the disciple of Mani, the Persian false prophet, the third century equivalent of Joseph Smith or Muhammed, who sent a Syriac speaker to the Fertile Crescent named Thomas (as St. Thomas the Apostle had set up the Christian church in Mesopotamia, Syria and was martyred in Kerala, India in 53 AD), to try to pass his religion off as a form of Christianity, but separately he sent to Egypt a disciple named Hermes who tried to sell the Manichaen faith to the followers of the Pagan cult of Hermes Trimegistus, and one called Buddha he sent to India and the Far East to market his faith to the Buddhists.
While the Manichees were briefly a thorn in the side of the Christian Church in the third and fourth century, with St. Augustine having been a Manichee before being baptized (importantly, his mother was a Christian, and together with St. Ambrose of Milan persuaded him to convert), over the long term, they slowly disappeared across Asia as the Church of the East expanded, and the last surviving Manichaean temple is in China and is disguised as a Buddhist temple, which is an example of the Middle Eastern religious practice of dissimulation, also engaged in by certain sects of Sufi Islam, and by adherents of the Gnostic heresy. It is rather creepy - you have an apparent Buddhist temple, which is creepy enough, in my opinion, but then certain symbols on it are unusual and the expression of the apparent idol of Buddha is not quite right - he is smiling - and these, combined with certain inscriptions on the wall which are quotes from Manichaean scriptures allow for the expert to identify the structure as being a Manichean temple disguised as a Buddhist temple.
Which makes one feel doubly sorry for the Buddhists who have historically worshipped there, for not only are they practicing a false and futile religion which has, with the spread of the Gospel to their land, gone from being a marginal source of moral instruction to being a toxic and detrimental counterfeit spirituality, which cannot fulfill any promises of salvation it offers (and what it promises is greatly inferior to what Christianity promises; indeed some forms of Buddhism literally promise nothing other than eventual non-reincarnation, and one supposes the enlightenment that adherenets of those forms of Buddhism sometimes rapidly receive is a realization of their own mortality and the falseness of the widespread Asian belief in reincarnation, which makes Buddhism, Hinduism, Jainism and SIkhism second-order superstitions, in that they propose to deliver one from reincarnation, which doesn’t happen to begin with. But these Buddhists intending to innocently practice their faith have been doing so alongside the last members of what was historically a non-violent but spiritually destructive cult which was known for its deliberate and systematic parallel impersonation of other religions, whose believers Manichaenism would parasitically try to influence to create a sort of syncretic faith, a counterfeit of the original religion infested with the false doctrines of Mani, such as his beliefs in dualism and certain other doctrines plagiarized from Zoroastrianism, Syrian Gnosticism and Pagan superstition, which were the sort of things Buddhists were supposed to avoid.
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In conclusion, while the Anglicans, Roman Catholics, and different Orthodox churches have slightly different Old Testament canons or deuterocanonical books which depart from the Masoretic canon favored by Presbyterians and Baptists (although John Calvin himself would have added Baruch to it, which he regarded as protocanonical), all major Christian churches including the Ethiopians, who count 1 Enoch and Jubilees among the canonical books of the Old Testament, agree that there are only 27 books, the same 27 books first listed by St. Athanasius of Alexandria in 367 AD, in his 39th Paschal Encyclical, in the New Testament.
The additional Old Testament material has not proven, contrary to the concerns of some Protestants from churches other than the traditional liturgical Protestant denominations where these books are permitted to be read, to be disruptive on issues of doctrine or morals; indeed some of the material, such as the Wisdom of Solomon, chapter 2, is particularly beautiful Christological prophecy, similiar to the Songs of the Suffering Servant by St. Isaiah.
1 Enoch is admittedly peculiar, however, the Ethiopians do not read it using literal-historical exegesis but as Christological prophecy, and thus it has no disruptive impact on their Christology, nor do they believe any strange things about giants or fallen angels or other things which some people derive from an odd literal reading of Genesis and 1 Enoch.
I would agree that people should avoid 1 Enoch, unless, and only unless, they are members of the Ethiopian Church and hear the book read or have a pastor in the Church who can explain it to them, or if they are familiar with the Alexandrian approach to Christological-typological prophecy, which some took to an extreme (one example of this which came frighteningly close to being included in the New Testament but which was stopped by St. Athanasius was the spurious epistle attributed to Barnabus) In the same way that some people of the present take a hyper-literal reading of the Old Testament to an extreme and prioritize that over a deep understanding of the Gospels, and focus their Christianity on speculation about whether or not Genesis is referring to dinosaurs, and other related issues which are not relevant to the Good News preached by Christ our True God. The most important early Church Fathers such as St. Athanasius, St. John Chrysostom, St. Basil the Great, St. Gregory the Theologian, St. Ambrose of Milan, St. Vincent of Lerins, St. Ephraim the Syrian and St. John of Damascus, among others, made versatile use of both the Alexandrian typological-prophetic hermeneutics and the approach taught in the rival Catechetical School of Antioch, that being literal-historical hermeneutics.
