Ignatius — Epistle to the Magnesians 10
Let us not, therefore, be insensible to His kindness. For were He to reward us according to our works, we should cease to be. Therefore, having become His disciples, let us learn to live according to the principles of Christianity. For whosoever is called by any other name besides this, is not of God. Lay aside, therefore, the evil, the old, the sour leaven, and be changed into the new leaven, which is Jesus Christ.
Be salted in Him, lest any one among you should be corrupted, since by your savour you shall be convicted. It is absurd to profess Christ Jesus, and to Judaize. For Christianity did not embrace Judaism, but Judaism Christianity, that so every tongue which believes might be gathered together to God.
Greek
Μὴ οὖν ἀναισθητῶμεν τῆς χρηστότητος αὐτοῦ. ἐὰν γὰρ ἡμᾶς μιμήσηται καθὰ πράσσομεν, οὐκέτι ἐσμέν. διὰ τοῦτο, μαθηταὶ αὐτοῦ γενόμενοι, μάθωμεν κατὰ Χριστιανισμὸν ζῆν. ὃς γὰρ ἄλλῳ ὀνόματι καλεῖται πλέον τούτου, οὐκ ἔστιν τοῦ θεοῦ. ὑπέρθεσθε οὖν τὴν κακὴν ζύμην, τὴν παλαιωθεῖσαν καὶ ἐνοξίσασαν, καὶ μεταβάλεσθε εἰς νέαν ζύμην, ὅ ἐστιν Ἰησοῦς Χριστός. ἁλίσθητε ἐν αὐτῷ, ἵνα μὴ διαφθαρῇ τις ἐν ὑμῖν, ἐπεὶ ἀπὸ τῆς ὀσμῆς ἐλεγχθήσεσθε. ἄτοπόν ἐστιν, Ἰησοῦν Χριστὸν λαλεῖν καὶ ἰουδαΐζειν. ὁ γὰρ Χριστιανισμὸς οὐκ εἰς Ἰουδαῖσμὸν ἐπίστευσεν, ἀλλ’ Ἰουδαϊσμὸς εἰς Χριστιανισμόν, ᾧ πᾶσα γλῶσσα πιστεύσασα εἰς θεὸν συνήχθη.