Jude

Who

Jude, who calls himself the brother of James — so most likely another brother of Jesus.

When

Somewhere between AD 50 and 90.

What it is

A short, hot warning against people who had slipped into the church and turned grace into permission.

What to watch for

It quotes 1 Enoch by name, which is why that book is on the Canon page here at all.

Beloved, although I made every effort to write to you about the salvation we share, I felt it necessary to write and urge you to contend earnestly for the faith entrusted once for all to the saints.Jude 1:3