Justin Martyr, The First Apology

And concerning our being patient of injuries, and ready to serve all, and free from anger, this is what He said: “To him that smiteth thee on the one cheek, offer also the other; and him that taketh away thy cloak or coat, forbid not. And whosoever shall be angry, is in danger of the fire. And every one that compelleth thee to go with him a mile, follow him two. And let your good works shine before men, that they, seeing them, may glorify your Father which is in heaven.”27 Luke vi. 29; Matt. vi. 22, 41, 16. For we ought not to strive; neither has He desired us to be imitators of wicked men, but He has exhorted us to lead all men, by patience and gentleness, from shame and the love of evil. And this indeed is proved in the case of many who once were of your way of thinking, but have changed their violent and tyrannical disposition, being overcome either by the constancy which they have witnessed in their neighbours’ lives,28 i.e., Christian neighbours. or by the extraordinary forbearance they have observed in their fellow-travellers when defrauded, or by the honesty of those with whom they have transacted business.

And with regard to our not swearing at all, and always speaking the truth, He enjoined as follows: “Swear not at all; but let your yea be yea, and your nay, nay; for whatsoever is more than these cometh of evil.”29 Matt. v. 34, 27. And that we ought to worship God alone, He thus persuaded us: “The greatest commandment is, Thou shalt worship the Lord thy God, and Him only shall thou serve, with all thy heart, and with all thy strength, the Lord God that made thee.”30 Mark xii. 30. And when a certain man came to Him and said, “Good Master,” He answered and said, “There is none good but God only, who made all things.”31 Matt. xix. 6, 17. And let those who are not found living as He taught, be understood to be no Christians, even though they profess with the lip the precepts of Christ; for not those who make profession, but those who do the works, shall be saved, according to His word: “Not every one who saith to Me, Lord, Lord, shall enter into the kingdom of heaven, but he that doeth the will of My Father which is in heaven. For whosoever heareth Me, and doeth My sayings, heareth Him that sent Me. And many will say unto Me, Lord, Lord, have we not eaten and drunk in Thy name, and done wonders? And then will I say unto them, Depart from Me, ye workers of iniquity. Then shall there be wailing and gnashing of teeth, when the righteous shall shine as the sun, and the wicked are sent into everlasting fire. For many shall come in My name, clothed outwardly in sheep’s clothing, but inwardly being ravening wolves. By their works ye shall know them. And every tree that bringeth not forth good fruit, is hewn down and cast into the fire.”32 Matt. vii. 21, etc.; Luke xiii. 26; Matt. xiii. 42, Matt. vii. 15, 16, 19. And as to those who are not living pursuant to these His teachings, and are Christians only in name, we demand that all such be punished by you.

[16] Περὶ δὲ τοῦ ἀνεξικάκους εἶναι καὶ ὑπηρετικοὺς πᾶσι καὶ ἀοργήτους ἃ ἔφη ταῦτά ἐστι: Τῷ τύπτοντί σου τὴν σιαγόνα πάρεχε καὶ τὴν ἄλλην, καὶ τὸν αἴροντά σου τὸν χιτῶνα ἢ τὸ ἱμάτιον μὴ κωλύσῃς. ὃς δ' ἂν ὀργισθῇ, ἔνοχός ἐστιν εἰς τὸ πῦρ. παντὶ δὲ ἀγγαρεύοντί σε μίλιον ἀκολούθησον δύο. λαμψάτω δὲ ὑμῶν τὰ καλὰ ἔργα ἔμπροσθεν τῶν ἀνθρώπων, ἵνα βλέποντες θαυμάζωσι τὸν πατέρα ὑμῶν τὸν ἐν τοῖς οὐρανοῖς. οὐ γὰρ ἀνταίρειν δεῖ: οὐδὲ μιμητὰς εἶναι τῶν φαύλων βεβούληται ἡμᾶς, ἀλλὰ διὰ τῆς ὑπομονῆς καὶ πραότητος ἐξ αἰσχύνης καὶ ἐπιθυμίας τῶν κακῶν ἄγειν πάντας προετρέψατο. ὃ γὰρ καὶ ἐπὶ πολλῶν τῶν παρ' ὑμῖν γεγενημένων ἀποδεῖξαι ἔχομεν: ἐκ βιαίων καὶ τυράννων μετέβαλον, ἡττηθέντες ἢ γειτόνων καρτερίαν βίου παρακολουθήσαντες ἢ συνοδοιπόρων πλεονεκτουμένων ὑπομονὴν ξένην κατανοήσαντες ἢ συμπραγματευομένων πειραθέντες. περὶ δὲ τοῦ μὴ ὀμνύναι ὅλως, τἀληθῆ δὲ λέγειν ἀεί, οὕτως παρεκελεύσατο: Μὴ ὀμόσητε ὅλως: ἔστω δὲ ὑμῶν τὸ ναὶ ναί, καὶ τὸ οὒ οὔ: τὸ δὲ περισσὸν τούτων ἐκ τοῦ πονηροῦ. ὡς δὲ καὶ τὸν θεὸν μόνον δεῖ προσκυνεῖν, οὕτως ἔπεισεν εἰπών: Μεγίστη ἐντολή ἐστι: Κύριον τὸν θεόν σου προσκυνήσεις καὶ αὐτῷ μόνῳ λατρεύσεις ἐξ ὅλης τῆς καρδίας σου καὶ ἐξ ὅλης τῆς ἰσχύος σου, κύριον τὸν θεὸν τὸν ποιήσαντά σε. καὶ προσελθόντος αὐτῷ τινος καὶ εἰπόντος: Διδάσκαλε ἀγαθέ, ἀπεκρίνατο λέγων: Οὐδεὶς ἀγαθὸς εἰ μὴ μόνος ὁ θεός, ὁ ποιήσας τὰ πάντα. οἳ δ' ἂν μὴ εὑρίσκωνται βιοῦντες, ὡς ἐδίδαξε, γνωριζέσθωσαν μὴ ὄντες Χριστιανοί, κἂν λέγωσιν διὰ γλώττης τὰ τοῦ Χριστοῦ διδάγματα: οὐ γὰρ τοὺς μόνον λέγοντας, ἀλλὰ τοὺς καὶ τὰ ἔργα πράττοντας σωθήσεσθαι ἔφη. εἶπε γὰρ οὕτως: Οὐχὶ πᾶς ὁ λέγων μοι Κύριε κύριε εἰσελεύσεται εἰς τὴν βασιλείαν τῶν οὐρανῶν, ἀλλ' ὁ ποιῶν τὸ θέλημα τοῦ πατρός μου τοῦ ἐν τοῖς οὐρανοῖς. ὃς γὰρ ἀκούει μου καὶ ποιεῖ ἃ λέγω ἀκούει τοῦ ἀποστείλαντός με. πολλοὶ δὲ ἐροῦσί μοι: Κύριε κύριε, οὐ τῷ σῷ ὀνόματι ἐφάγομεν καὶ ἐπίομεν καὶ δυνάμεις ἐποιήσαμεν; καὶ τότε ἐρῶ αὐτοῖς: Ἀποχωρεῖτε ἀπ' ἐμοῦ, ἐργάται τῆς ἀνομίας. τότε κλαυθμὸς ἔσται καὶ βρυγμὸς τῶν ὀδόντων, ὅταν οἱ μὲν δίκαιοι λάμψωσιν ὡς ὁ ἥλιος, οἱ δὲ ἄδικοι πέμπωνται εἰς τὸ αἰώνιον πῦρ. πολλοὶ γὰρ ἥξουσιν ἐπὶ τῷ ὀνόματί μου, ἔξωθεν μὲν ἐνδεδυμένοι δέρματα προβάτων, ἔσωθεν δὲ ὄντες λύκοι ἅρπαγες: ἐκ τῶν ἔργων αὐτῶν ἐπιγνώσεσθε αὐτούς. πᾶν δὲ δένδρον, μὴ ποιοῦν καρπὸν καλόν, ἐκκόπτεται καὶ εἰς πῦρ βάλλεται. κολάζεσθαι δὲ τοὺς οὐκ ἀκολούθως τοῖς διδάγμασιν αὐτοῦ βιοῦντας, λεγομένους δὲ μόνον Χριστιανούς, καὶ ὑφ' ὑμῶν ἀξιοῦμεν.