What does the Bible say about the book of Jude?

The book of Jude, authored by Jude, the brother of James, serves as a general epistle directed toward all God's people rather than a specific individual or church. It addresses foundational themes such as the assurance of God's keeping power over His elect and a strong warning against heresies that arise within the church. Jude emphasizes that the nature of man and God's promise of salvation remains unchanged across ages, reassuring believers of God's unvarying character and faithfulness to those who are sanctified and preserved in Christ.