Is it a sin to read the Book of Enoch?
Jude quotes it, and almost no church includes it

In short
No text forbids reading anything. The Book of Enoch is quoted in Jude and was known to the early church, but only the Ethiopian Orthodox Church treats it as Scripture. Reading it as history or as background is uncontroversial; treating it as canonical is where the disagreement starts.
What the text says
And Enoch also, the seventh from Adam, prophesied of these, saying, Behold, the Lord cometh with ten thousands of his saints,
2 Timothy 3:16 was the verse of the day on January 8, 2022. See that day
Often brought in2 Timothy 3:16
All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:
Scripture is described by what it does. The question about Enoch is whether it belongs in that category, which this verse raises but does not answer.
The counterweightRevelation 22:18
For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book:
Often quoted against reading extra books, though it refers to the prophecy of Revelation itself rather than to a closed canon. Reading it as a rule about the whole Bible goes past what it says.
What Christians agree on
The Book of Enoch existed and was read in the first century, and Jude quotes it. Nearly every tradition holds that quotation does not confer canonical status - Paul quotes pagan poets too.
Where they disagree
The Ethiopian Orthodox Church
Enoch is canonical Scripture and has been since antiquity. That most churches lost it is a matter of history rather than a judgement they should follow.
Most Christian traditions
It is useful early literature and not Scripture. The church tested books over centuries and did not receive this one; being quoted is not the same as being canonical.
Those who counsel caution
Reading it is not sin, but its picture of angels and cosmology has produced a good deal of confusion. Read it knowing what it is, or not at all.
Questions worth asking
- Am I reading this to understand the first century, or hoping for something hidden?
- Would I know how to tell the difference between old and authoritative?
- Is there someone I could read it alongside, rather than alone on the internet?
The idea that certain books were suppressed makes a better story than the truth, which is that the church argued about them in public for centuries. Enoch is not forbidden; it just lost the argument almost everywhere.