The Book of Enoch, while not accepted in general as canonical, is accepted as such by Ethiopian Jews, as well as by some Orthodox churches. And whether considered as inspired or not, it was likely respected by the early Christians, as the book of Jude quotes from it, saying,

It was also about these that Enoch, in the seventh generation from Adam, prophesied, saying, “See, the Lord is coming with ten thousands of his holy ones, to execute judgment on all, and to convict everyone of all the deeds of ungodliness that they have committed in such an ungodly way, and of all the harsh things that ungodly sinners have spoken against him.”

This is a quotation from the end of the first chapter of the book of Enoch.

Chapter 46 describes a vision of Enoch:

46:1   At that place, I saw the One to whom belongs the time before time. And his head was white like wool, and there was with him another individual, whose face was like that of a human being. His countenance was full of splendor like that of one among the kodesh malakim.

46:2   And I asked the one -from among the malakim -who was going with me, and who had revealed to me all the secrets regarding the One who was born of human beings, “Who is this, and from whence is he who is going as the prototype of the Before -Time?”

46:3   And he answered me and said to me, “This is the Son of Man, to whom belongs righteousness, and with whom righteousness dwells. And He will open all the hidden storerooms; for YAHWEH of Hosts has chosen Him, and He is destined to be victorious before YAHWEH of Hosts in eternal uprightness.”

46:4   “This Son of Man whom you have seen is the One who would remove the kings and the mighty ones from their comfortable seats and the strong ones from their thrones. He shall loosen the reins of the strong and crush the teeth of the sinners.”

46:5   “He shall depose the kings from their thrones and kingdoms. For they do not extol and magnify HIM, and neither do they obey HIM, the source of their kingship.”

46:6   “The faces of the strong will be slapped and be filled with shame and gloom. Their dwelling places and their beds will be worms. They shall have no hope to rise from their beds, for they do not extol the NAME of YAHWEH of Hosts.”

46:7   “And they have become the judges of the stars of heaven; they raise their hands to reach YAHWEH the Most High while walking upon the earth and dwelling in her. They manifest all their deeds in oppression; all their deeds are oppression. Their power depends upon their wealth. And their devotion is to the gods which they have fashioned with their own hands. But they deny the NAME of YAHWEH of Hosts.”

46:8   “Yet they like to congregate in HIS houses and with the faithful ones who cling to YAHWEH of Hosts.

The Son of Man is the one “to whom belongs righteousness, and with whom righteousness dwells,” and the following verses indicate the he is the one who was chosen by God to execute justice.

The reason why the kings are deposed is that “they do not extol and magnify him, neither do they obey him, the source of their kingship.” The translator in this case seems to interpret this to refer to God, and thus capitalizes “him,” but the most obvious understanding of the pronoun would be that it refers to the Son of Man. Nonetheless, the fact that he is the source of their kingship might suggest that he is also God in fact, and this is also suggested by the fact that the text goes on to say, “They shall have no hope to rise from their beds, for they do not extol the name of Yahweh of hosts.” This at least suggests that not praising the Son of Man is the same as not praising God.

Chapter 47 describes why a judgment is necessary in the first place:

47:1   “In those days, the prayers of the righteous ascended into heaven, and the blood of the righteous from the earth before YAHWEH of Hosts.”

47:2   “There shall be days when all the kodesh ones who dwell in the heavens above shall dwell together. And with one voice, they shall supplicate and pray -magnifying, praising, and blessing the NAME of YAHWEH of Hosts -on behalf of the blood of the righteous ones which has been shed. Their prayers shall not stop from exhaustion before YAHWEH of Hosts -neither will they relax forever -until judgment is executed for them.”

47:3   In those days, I saw Him -the Antecedent of Time, while He was sitting upon the throne of his splendor, and the books of the living ones were open before Him. And all His power in heaven above and His escorts stood before Him.

47:4   The hearts of the kodesh ones are filled with joy, because the number of the righteous has been offered, the prayers of the righteous ones have been heard, and the blood of the righteous has been admitted before YAHWEH of Hosts.

Thus judgment is needed to correct the injustice done to the just by the wicked. Chapter 48 seems to describe the Son of Man as preexisting and as having a predestined role of carrying out the needed judgment:

48:1   Furthermore, in that place I saw the fountain of righteousness, which does not become depleted and is surrounded completely by numerous fountains of wisdom.

48:2   All the thirsty ones drink of the water and become filled with wisdom. Then their dwelling places become with the kodesh, righteous, and elect ones.

48:3   At that hour, that Son of Man was given a name, in the presence of YAHWEH of Hosts, the Before Time; even before the creation of the sun and the moon, before the creation of the stars, He was given a name in the presence of YAHWEH of Hosts.

48:4   He will become a staff for the righteous ones in order that they may lean on Him and not fall. He is the Light of the gentiles and He will become the hope of those who are sick in their hearts.

48:5   All those who dwell upon the earth shall fall and worship before Him; they shall magnify, bless, and sing the NAME of YAHWEH of Hosts.

48:6   For this purpose He became the Chosen One; He was concealed in the presence of YAHWEH of Hosts prior to the creation of the world, and for eternity.

48:7   And He has revealed the wisdom of YAHWEH of Hosts to the righteous and the kodesh ones, for He has preserved the portion of the righteous because they have hated and despised this world of oppression together with all its ways of life and its habits in the NAME of YAHWEH of Hosts; and because they will be saved in His Name and it is His good pleasure that they have life.

48:8   In those days, the kings of the earth and the mighty landowners shall be humiliated on account of the deeds of their hands. Therefore, on the day of their misery and weariness, they will not be able to save themselves.

48:9   I shall deliver them into the hands of MY elect ones like grass in the fire and like lead in the water, so they shall burn before the face of the kodesh ones and sink before their sight, and no place will be found for them.

48:10   On the day of their weariness, there shall be an obstacle on the earth and they shall fall on their faces; and they shall not rise up again, nor anyone be found who will take them with his hands and raise them up. For they have denied YAHWEH of Hosts and HIS Messiah. Blessed be the NAME of YAHWEH of Hosts!

While one might think that being concealed in the presence of God before the creation of the world might imply only the divine predestination, it would not be unreasonable to read this as implying an eternal preexistence of the Son of Man, even if not in the condition of a man. And it seems that “they will be saved in His Name,” and “it is His good pleasure that they have life,” also refer to the Son of Man. In fact, overall it seems that considered in itself, God would have the role of saving and giving life, and judging the wicked, but in practice God chooses to give these roles to the Son of Man.

Finally, at the end of the text, the Son of Man is identified as the Messiah.