Heidegger's Bible Handbook: Jude: Recipients
3. The Inscription.
Now, Jude wrote τοῖς ἐν Θεῷ Πατρὶ ἡγιασμένοις, καὶ Ἰησοῦ Χριστῷ τετηρημένοις, κλητοῖς, to those sanctified in God the Father, and preserved by Jesus Christ, and called, verse 1. Undoubtedly are understood all believers of the Jews and Gentiles, called to the communion of the Kingdom of Christ, into whose hands this truly Catholic Epistle, as it is also called in its inscription, may have fallen.