Words And Deeds

Ὁ χείλεσι μόνον ὁμολογῶν τὸν Χριστὸν, ἀρνησάμενος δὲ τοῖς ἔργοις, οὐκ ἔστιν ἐν αὐτῷ , οὐδε ἔχει αὐτὸν ἐν ἑαυτοῦ· μόνον καὶ παντὸς μετόχου τυγχάνοντος τοῦ εν αὐτῷ πάντα ποιοῦντος . Δίδυμος Αλεξανδρεύς, Εἰς τον Προφήτην Ησαΐαν Source:  Migne PG 95.1169c

He who with lips alone confesses Christ, denying Him in works, 1 He is not in him, nor does he have Him in himself; 2 indeed the only one who participates fully in Him is he who does everything in Him. Didymus the Blind, On Isaiah, quoted in the Sacred Parallels of Saint John of Damascus 1 cf Isaiah 29.13, Mt 15.8 2 cf Jn 14.20-21