Live as Christians, not as Jews
Ignatius is writing to the Magnesians, urging them to abandon old ways and live fully as Christians in Christ.
So let us not be numb to His kindness. For if He should deal with us according to what we do, we no longer exist. Therefore, since we have become His disciples, let us learn to live according to Christianity. For whoever is called by any other name than this is not of God.
Put away, then, the evil leaven, which has grown old and turned sour, and change into new leaven, which is Jesus Christ. Be preserved in Him, so that no one among you may be corrupted, since by your fragrance you will be recognized.
It is absurd to speak of Jesus Christ and to Judaize. For Christianity did not come to faith through Judaism, but Judaism through Christianity, in which every tongue that has believed in God has been gathered together.
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.