The author of this brief Epistle, who describes himself as “the brother of James,” is customarily identified with the Apostle Judas (Luke 6:16)—not of course Judas Iscariot. It is also thought possible that the letter was by Judas, a brother of Jesus (Matthew 13:55).
Jude, the servant of Jesus Christ, and brother of James, to them that are sanctified by God the Father, and preserved in Jesus Christ, and called.1:1
It was needful for me to write unto you, and exhort you. . . .
For there are certain men crept in unawares . . . ungodly men, turning the grace of our God into lasciviousness, and denying the only Lord God, and our Lord Jesus Christ.3:4
These are spots in your feasts of charity . . . clouds they are without water, carried about of winds. . . .
Raging waves of the sea, foaming out their own shame; wandering stars, to whom is reserved the blackness of darkness for ever.12:13