What does the Bible say about Jude's authorship?

In Jude 1, the author identifies himself as Jude, the servant of Jesus Christ and brother of James. This introduction reveals a profound humility, as he does not emphasize his earthly relationship to Christ but rather his servitude. Jude’s name is notably shared with Judas, the betrayer, drawing a contrast between two individuals who share a common origin but diverged through the sovereign grace of God. Jude’s authorship underscores the theme of divine mercy extended to one who was just as deserving of wrath as others, relying solely on God's grace for his commission to write scripture.