Anyone who does a modicum of research into ancient christianity; they'll find all the early church father's quoted Enoch as inspired.  Also, Enoch is quoted in Jude. So is Jasher. In fact Enoch himself said this book was for the latter generation, the one who shall be witnesses to the 2nd coming of Christ. He (Enoch) even identifies himself as one of the two witnesses spoken of in Revelation.
 
It wasn't until the Sethite position appeared around the 4th century, that this work was starting to be rejected. One of the oldest bibles, the Ethiopic contains Enoch in their Canon.
 
I have looked into the Sethite position, and it fails to answer many facts the bible teaches about the giants, and the sons of God. How can the sons of God be men, when in Job 38:7, they shouted for joy when God laid the foundation of the earth!
 
Man did not even exist yet! The bible teaches man is created from the dust of the earth. These are important facts the Sethite teachers ignore, and pretend do not exist.
 
They are forced to allegorize scripture, and ignore the literal. Spiritualizing it away into almost meaningless nonsense. I pray people search into these matters for themselves.
 
I really haven't felt much of need to speak about this, Donna and others are doing a fine job. God Bless