Theophilus of Antioch, To Autolycus 1.5
Just as the soul within a human being is not seen — it is invisible to human eyes — yet is perceived through the body's movement, so also God cannot be seen by human eyes, but is seen and perceived through His providence and works. Just as someone who sees a ship at sea, equipped and sailing into harbor, clearly infers that a helmsman is aboard steering it, so we must understand God to be the helmsman of all things, even though He is not seen with fleshly eyes because He is incorporeal. For if a human cannot gaze at the sun, a mere element, due to its excessive heat and power, how much more impossible is it for a mortal human to look upon the incomprehensible glory of God? Just as a pomegranate has a rind surrounding it, and inside contains many seeds and compartments separated by membranes — many seeds dwelling within it — so all creation is surrounded by the Spirit of God, and the Spirit surrounding creation is in turn surrounded by the hand of God. Just as a pomegranate seed dwelling inside cannot see what lies outside the rind, being inside, so also a human being, surrounded along with all creation by the hand of God, cannot see God. An earthly king is believed to exist even though not seen by all, for he is perceived through his laws, orders, authorities, powers, and images. Why then do you refuse to perceive God through His works and powers?
Greek
Καθάπερ γὰρ ψυχὴ ἐν ἀνθρώπῳ οὐ βλέπεται, ἀόρατος οὖσα ἀνθρώποις, διὰ δὲ τῆς κινήσεως τοῦ σώματος νοεῖται ἡ ψυχή, οὕτως ἔχοι ἂν καὶ τὸν θεὸν μὴ δύνασθαι ὁραθῆναι ὑπὸ ὀφθαλμῶν ἀνθρωπίνων, διὰ δὲ τῆς προνοίας καὶ τῶν ἔργων αὐτοῦ βλέπεται καὶ νοεῖται. Ὃν τρόπον γὰρ καὶ πλοῖον θεασάμενός τις ἐν θαλάσσῃ κατηρτισμένον καὶ τρέχον καὶ κατερχόμενον εἰς λιμένα δῆλον ὅτι ἡγήσεται εἶναι ἐν αὐτῷ κυβερνήτην τὸν κυβερνῶντα αὐτό, οὕτως δεῖ νοεῖν εἶναι τὸν θεὸν κυβερνήτην τῶν ὅλων, εἰ καὶ οὐ θεωρεῖται ὀφθαλμοῖς σαρκίνοις διὰ τὸ αὐτὸν ἀχώρητον εἶναι. Εἰ γὰρ τῷ ἡλίῳ ἐλαχίστῳ ὄντι στοιχείῳ οὐ δύναται ἄνθρωπος ἀτενίσαι διὰ τὴν ὑπερβάλλουσαν θέρμην καὶ δύναμιν, πῶς οὐχὶ μᾶλλον τῇ τοῦ θεοῦ δόξῃ ἀνεκφράστῳ οὔσῃ ἄνθρωπος θνητὸς οὐ δύναται ἀντωπῆσαι; Ὃν τρόπον γὰρ ῥοά, ἔχουσα φλοιὸν τὸν περιέχοντα αὐτήν, ἔνδον ἔχει μονὰς καὶ θήκας πολλὰς διαχωριζομένας διὰ ὑμένων καὶ πολλοὺς κόκκους ἔχει τοὺς ἐν αὐτῇ κατοικοῦντας, οὕτως ἡ πᾶσα κτίσις περιέχεται ὑπὸ πνεύματος θεοῦ, καὶ τὸ πνεῦμα τὸ περιέχον σὺν τῇ κτίσει περιέχεται ὑπὸ χειρὸς θεοῦ· ὥσπερ οὖν ὁ κόκκος τῆς ῥοᾶς ἔνδον κατοικῶν οὐ δύναται ὁρᾶν τὰ ἔξω τοῦ λέκους, αὐτὸς ὤν ἔνδον, οὕτως οὐδὲ ἄνθρωπος ἐμπεριεχόμενος μετὰ πάσης τῆς κτίσεως ὑπὸ χειρὸς θεοῦ οὐ δύναται θεωρεῖν τὸν θεόν.Εἶτα βασιλεὺς μὲν ἐπίγειος πιστεύεται εἶναι, καίπερ μὴ πᾶσιν βλεπόμενος, διὰ δὲ νόμων καὶ διατάξεων αὐτοῦ καὶ ἐξουσιῶν καὶ δυνάμεων καὶ εἰκόνων νοεῖται. Τὸν δὲ θεὸν οὐ βούλει σὺ νοεῖσθαι διὰ ἔργων καὶ δυνάμεων;