Athenagoras, Plea for the Christians 10
That we are not atheists has been shown to me sufficiently, for we hold to one God, unborn, eternal, invisible, impassible, incomprehensible, and uncircumscribed, who is apprehended by mind and reason alone and encompassed by light, beauty, spirit, and indescribable power. Through his own Reason all things have been made, adorned, and are held together. We also acknowledge the Son of God. Let no one think it laughable that the Son belongs to God. We have not thought of God and Father, nor of the Son, as poets mythologize, making the gods no better than men. Rather, the Son of God is the Reason of the Father in idea and in energy; for through him and on account of him all things were made, the Father and the Son being one. Since the Son is in the Father and the Father in the Son, by unity and power of Spirit, the Son of God is the mind and Reason of the Father. If you are persuaded to consider this by excess of understanding, I will say briefly what the Child desires: he is the firstborn of the Father, not as having been made (for God was from the beginning, an eternal mind, having the Reason in himself eternally, being eternally rational), but as idea and energy proceeding, all material things having been subjected — of useless nature and useless earth — the denser things mixed with the lighter upon them. The prophetic Spirit agrees with the Reason; for it says, "The Lord created me the beginning of his ways for his works" (Proverbs 8:22). We also say that the Holy Spirit which energizes those who speak prophetically is an effluence of God, flowing out and reflected back like a ray of the sun.
Who then would not be at a loss, hearing us called atheists while we speak of God the Father, the Son of God, and the Holy Spirit, showing both their power in unity and their distinction in order? Our theological account does not rest on these things alone; we also affirm a multitude of angels and ministers, whom the Maker and Creator of the world, God, has distributed and ordered through his Reason which is with him, to govern the elements, the heavens, the world, the things in it, and their good order.
Greek
Τὸ μὲν οὖν ἄθεοι μὴ εἶναι, ἕνα τὸν ἀγένητον καὶ ἀΐδιον καὶ ἀόρατον καὶ ἀπαθῆ καὶ ἀκατάληπτον καὶ ἀχώρητον, νῷ μόνῳ καὶ λόγῳ καταλαμβανόμενον, φωτὶ καὶ κάλλει καὶ πνεύματι καὶ δυνάμει ἀνεκδιηγήτῳ περιεχόμενον, ὑφ᾿ οὗ γεγένηται τὸ πᾶν διὰ τοῦ αὐτοῦ λόγου καὶ διακεκόσμηται καὶ συγκρατεῖται, θεὸν ἄγοντες, ἱκανῶς μοι δέδεικται. Νοοῦμεν γὰρ καὶ υἱὸν τοῦ θεοῦ. Καὶ μή μοι γελοῖόν τις νομίσῃ τὸ υἱὸν εἶναι τῷ θεῷ. Οὐ γὰρ ὡς ποιηταὶ μυθοποιοῦσιν, οὐδὲν βελτίους τῶν ἀνθρώπων δεικνῦντες τοὺς θεούς, ἢ περὶ τοῦ θεοῦ καὶ πατρὸς ἢ περὶ τοῦ υἱοῦ πεφρονήκαμεν. Ἀλλ᾿ ἔστιν ὁ υἱὸς τοῦ θεοῦ λόγος τοῦ πατρὸς ἐν ἰδέᾳ καὶ ἐνεργείᾳ· πρὸς αὐτοῦ γὰρ καὶ δι᾿ αὐτοῦ πάντα ἐγένετο, ἑνὸς ὄντος τοῦ πατρὸς καὶ τοῦ υἱοῦ. Ὄντος δὲ τοῦ υἱοῦ ἐν πατρὶ καὶ πατρὸς ἐν υἱῷ, ἑνότητι καὶ δυνάμει πνεύματος, νοῦς καὶ λόγος τοῦ πατρὸς ὁ υἱὸς τοῦ θεοῦ. Εἰ δὲ δι᾿ ὑπερβολὴν συνέσεως σκοπεῖν ὑμῖν ἔπεισιν, ὁ παῖς τί βούλεται, ἐρῶ διὰ βραχέων πρῶτον γέννημα εἶναι τῷ πατρί, οὐχ ὡς γενόμενον (ἐξ ἀρχῆς γὰρ ὁ θεός, νοῦς ἀΐδιος ὤν, εἶχεν αὐτὸς ἐν ἑαυτῷ τὸν λόγον, ἀϊδίως λογικὸς ὤν), ἀλλ᾿ ὡς τῶν ὑλικῶν ξυμπάντων, ἀποίου φύσεως καὶ γῆς ἀχρείας ὑποκειμένων δίκην, μεμιγμένων τῶν παχυμερεστέρων πρὸς τὰ κουφότερα ἐπ᾿ αὐτοῖς, ἰδέα καὶ ἐνέργεια εἶναι προελθών. Συνᾴδει δὲ τῷ λόγῳ καὶ τὸ προφητικὸν πνεῦμα· Κύριος γάρ, φησίν, ἔκτισέ με ἀρχὴν ὁδῶν αὐτοῦ εἰς ἔργα αὐτοῦ. Καίτοι καὶ αὐτὸ τὸ ἐνεργοῦν τοῖς ἐκφωνοῦσι προφητικῶς ἅγιον πνεῦμα ἀπόῤῥοιαν εἶναί φαμεν τοῦ θεοῦ, ἀποῤῥέον καὶ ἐπαναφερόμενον ὡς ἀκτῖνα ἡλίου.Τίς οὖν οὐκ ἂν ἀπορήσαι, λέγοντας θεὸν πατέρα καὶ υἱὸν θεὸν καὶ πνεῦμα ἅγιον, δεικνύντας αὐτῶν καὶ τὴν ἐν τῇ ἑνώσει δύναμιν καὶ τὴν ἐν τῇ τάξει διαίρεσιν, ἀκούσας ἀθέους καλουμένους; Καὶ οὐκ ἐπὶ τούτοις τὸ θεολογικὸν ἡμῶν ἵσταται μέρος· ἀλλὰ καὶ πλῆθος ἀγγέλων καὶ λειτουργῶν φαμεν, οὓς ὁ ποιητὴς καὶ δημιουργὸς κόσμου θεὸς διὰ τοῦ παρ᾿ αὐτοῦ λόγου διένειμε καὶ διέταξε περί τε τὰ στοιχεῖα εἶναι καὶ τοὺς οὐρανοὺς καὶ τὸν κόσμον καὶ τὰ ἐν αὐτῷ καὶ τὴν τούτων εὐταξίαν.