Epistle to Diognetus

Come then, clear thyself of all the prepossessions which occupy thy mind, and throw off the habit which leadeth thee astray, and become a new man, as it were, from the beginning, as one who would listen to a new story, even as thou thyself didst confess. See not only with thine eyes, but with thine intellect also, of what substance or of what form they chance to be whom ye call and regard as gods.

Ἄγε δή, καθάρας σεαυτὸν ἀπὸ πάντων τῶν προκατεχόντων σου τὴν διάνοιαν λογισμῶν καὶ τὴν ἀπατῶσάν σε συνήθειαν ἀποσκευασάμενος καὶ γενόμενος ὥσπερ ἐξ ἀρχῆς καινὸς ἄνθρωπος, ὡς ἂν καὶ λόγου καινοῦ, καθάπερ καὶ αὐτὸς ὡμολόγησας, ἀκροατὴς ἐσόμενος: ἴδε μὴ μόνον τοῖς ὀφθαλμοῖς, ἀλλὰ καὶ τῇ φρονήσει, τίνος ὑποστάσεως ἢ τίνος εἴδους τυγχάνουσιν, οὓς ἐρεῖτε καὶ νομίζετε θεούς.