Letter 213: Secular power and spiritual authority are different things and must not be confused.

To Cyril [of Alexandria] On the saying, "Unless your righteousness exceeds that of the Scribes," and that this does not contradict "Woe to you, Scribes." Since you supposed that some contradiction perhaps lay in the holy Gospels, you wrote that the Savior said to the Pharisees, as men devoid of virtue, "Woe to you, Scribes and Pharisees, hypocrites"; but to the apostles, "Unless your righteousness exceeds that of the Scribes and Pharisees, you shall by no means enter into the kingdom of heaven." You write back in reply that one must understand the word "exceeds" to be said with reference to the righteousness which it would have been fitting, or rather which it was their duty, to have possessed. For it is not those who sail with the men who are pronounced wretched and bewailed who would justly reign, but those who surpass, by a great margin, the men esteemed according to the Law, and who have conducted a manner of life befitting heaven.

Εἰς τὸ εἰρημένον· «Ἐὰν μὴ περισσεύσῃ ἡ δικαιοσύνη ὑμῶν πλέον τῶν Γραμματέων·» καὶ ὅτι τοῦτο οὐκ ἐναντιοῦται τῷ, «Οὐαὶ ὑμῖν, Γραμματεῖς.» Ἐπειδὴ ἴσως ἐναντιολογίαν τινὰ ἐνόμισας (78) κεῖσθαι ἐν τοῖς ἱεροῖς Εὐαγγελίοις, γέγραφας, εἰρηκέναι τὸν Σωτῆρα, τοῖς μὲν Φαρισαίοις ὡς ἐρήμοις ἀρετῆς· «Οὐαὶ ὑμῖν, Γραμματεῖς, καὶ Φαρισαῖοι, ὑποκριταί·» τοῖς δ᾽ ἀποστόλοις, «Ἐὰν μὴ περισσεύσῃ ὑμῶν ἡ δικαιοσύνη πλέον τῶν Γραμματέων καὶ Φαρισαίων, οὐ μὴ εἰσέλθητε εἰς τὴν βασιλείαν τῶν οὐρανῶν.» Ἀντεπιστέλλεις, ὅτι νοεῖν χρή, πλέον, εἰρῆσθαι, τῆς δικαιοσύνης ἧς εἰκὸς, μᾶλλον δὲ ἐχρῆν ἐκείνους ἔχειν. Οὐ γὰρ οἱ τῶν ταλανιζομένων καὶ καταθρηνουμένων πλέοντες (79), βασιλεῦσαι δίκαιοι ἂν εἶεν· ἀλλ᾽ οἱ τοὺς κατὰ νόμον εὐδοκίμους ἐκ πολλοῦ τοῦ περιόντος ὑπερβαίνοντες, καὶ οὐρανῷ πρέπουσαν πολιτείαν πολιτευσάμενοι (80).