God revealed himself through faith alone
The author is arguing that no human being could know God before the Son came, and that God revealed himself through faith.
Who among human beings had any idea at all what God is before he came? Or do you accept those empty and foolish arguments of the philosophers who are considered trustworthy? Some of them said that God is fire, and they call the very thing they are going to end up in God. Others said water, and others one or another of the elements that were created by God. And yet, if any of these arguments were acceptable, then each of the other created things could just as easily be declared God. But all this is the wonder-working and deceit of charlatans. No human being has ever seen God or known him, but he has shown himself. He has shown himself through faith, and through faith alone has it been granted to see God.
For God, the Master and Maker of all things, who made everything and set it in order, was not only loving toward humanity but also patient. He was always like this, and is, and will be: kind and good and without anger and true, and he alone is good. But when he conceived a great and unutterable thought, he shared it with his child alone. So as long as he kept his wise plan hidden in mystery and guarded it, he seemed to neglect us and take no thought for us. But when he revealed it through his beloved child and made known what had been prepared from the beginning, he gave us everything at once: to share in his benefits, and to see and understand things that none of us could ever have expected.
Greek
Τίς γὰρ ὅλως ἀνθρώπων ἠπίστατο, τί ποτ̓ ἐστὶ θεὸς πρὶν αὐτὸν ἐλθεῖν;
ἢ τοὺς κενοὺς καὶ ληρώδεις ἐκείνων λόγους ἀποδέχῃ τῶν ἀξιοπίστων φιλοσόφων, ὧν οἱ μέν τινες πῦρ ἔφασαν εἶναι τὸν θεὸν ʽοὗ μέλλουσι χωρήσειν αὐτοί, τοῦτο καλοῦσι θεόν̓, οἱ δὲ ὕδωρ, οἱ δ’ ἄλλο τι τῶν στοιχείων τῶν ἐκτισμένων ὑπὸ θεοῦ;
καίτοι γε, εἴ τις τούτων τῶν λόγων ἀποδεκτός ἐστι, δύναιτ̓ ἂν καὶ τῶν λοιπῶν κτισμάτων ἓν ἕκαστον ὁμοίως ἀποφαίνεσθαι θεόν.
ἀλλὰ ταῦτα μὲν τερατεία καὶ πλάνη τῶν γοήτων ἐστίν:
ἀνθρώπων δὲ οὐδεὶς οὔτε εἶδεν οὔτε ἐγνώρισεν, αὐτὸς δὲ ἑαυτὸν ἐπέδειξεν.
ἐπέδειξε δὲ διὰ πίστεως, ᾗ μόνῃ θεὸν ἰδεῖν συγκεχώρηται.
ὁ γὰρ δεσπότης καὶ δημιουργὸς τῶν ὅλων θεός, ὁ ποιήσας τὰ πάντα καὶ κατὰ τάξιν διακρίνας, οὐ μόνον φιλάνθρωπος ἐγένετο, ἀλλὰ καὶ μακρόθυμος.
ἀλλ’ οὗτος ἦν μὲν ἀεὶ τοιοῦτος καὶ ἔστι καὶ ἔσται, χρηστὸς καὶ ἀγαθὸς καὶ ἀόργητος καὶ ἀληθής, καὶ μόνος ἀγαθός ἐστιν:
ἐννοήσας δὲ μεγάλην καὶ ἄφραστον ἔννοιαν ἀνεκοινώσατο μόνῳ τῷ παιδί.
ἐν ὅσῳ μὲν οὖν κατεῖχεν ἐν μυστηρίῳ καὶ διετήρει τὴν σοφὴν αὐτοῦ βουλήν, ἀμελεῖν ἡμῶν καὶ ἀφροντιστεῖν ἐδόκει:
ἐπεὶ δὲ ἀπεκάλυψε διὰ τοῦ ἀγαπητοῦ παιδὸς καὶ ἐφανέρωσε τὰ ἐξ ἀρχῆς ἡτοιμασμένα, πάνθ̓ ἅμα παρέσχεν ἡμῖν καὶ μετασχεῖν τῶν εὐεργεσιῶν αὐτοῦ καὶ ἰδεῖν καὶ νοῆσαι, ἃ τίς ἂν πώποτε προσεδόκησεν ἡμῶν;