St. Ignatius of Antioch:
Chapter X.—Beware of Judaizing.
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.695 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 ye changed into the new leaven, which is Jesus Christ. Be ye salted in Him, lest any one among you should be corrupted, since by your savour ye shall be convicted. It is absurd to profess696 Christ Jesus, and to Judaize. For Christianity did not embrace697 Judaism, but Judaism Christianity, that so every tongue which believeth might be gathered together to God.
Let us not, therefore, be insensible to His kindness. For were He to reward us according to our works, we should cease to be. For “if Thou, Lord, shalt mark iniquities, O Lord, who shall stand?”698 Let us therefore prove ourselves worthy of that name which we have received. For whosoever is called by any other name besides this, he is not of God; for he has not received the prophecy which speaks thus concerning us: “The people shall be called by a new name, which the Lord shall name them, and shall be a holy people.”699 This was first fulfilled in Syria; for “the disciples were called Christians at Antioch,”700 when Paul and Peter were laying the foundations of the Church. Lay aside, therefore, the evil, the old, the corrupt leaven,701 and be ye changed into the new leaven of grace. Abide in Christ, that the stranger702 may not have dominion over you. It is absurd to speak of Jesus Christ with the tongue, and to cherish in the mind a Judaism which has now come to an end. For where there is Christianity there cannot be Judaism. For Christ is one, in whom every nation that believes, and every tongue that confesses, is gathered unto God. And those that were of a stony heart have become the children of Abraham, the friend of God;703 and in his seed all those have been blessed704 who were ordained to eternal life705 in Christ.
Chapter VI.—Do not accept Judaism.
But if any one preach the Jewish law923 unto you, listen not to him. For it is better to hearken to Christian doctrine from a man who has been circumcised, than to Judaism from one uncircumcised. But if either of such persons do not speak concerning Jesus Christ, they are in my judgment but as monuments and sepulchres of the dead, upon which are written only the names of men. Flee therefore the wicked devices and snares of the prince 83 of this world, lest at any time being conquered924 by his artifices,925 ye grow weak in your love. But be ye all joined together926 with an undivided heart. And I thank my God that I have a good conscience in respect to you, and that no one has it in his power to boast, either privately or publicly, that I have burdened927 any one either in much or in little. And I wish for all among whom I have spoken, that they may not possess that for a testimony against them.
If any one preaches the one God of the law and the prophets, but denies Christ to be the Son of God, he is a liar, even as also is his father the devil,928 and is a Jew falsely so called, being possessed of929 mere carnal circumcision. If any one confesses Christ Jesus the Lord, but denies the God of the law and of the prophets, saying that the Father of Christ is not the Maker of heaven and earth, he has not continued in the truth any more than his father the devil,930 and is a disciple of Simon Magus, not of the Holy Spirit. If any one says there is one God, and also confesses Christ Jesus, but thinks the Lord to be a mere man, and not the only-begotten931 God, and Wisdom, and the Word of God, and deems Him to consist merely of a soul and body, such an one is a serpent, that preaches deceit and error for the destruction of men. And such a man is poor in understanding, even as by name he is an Ebionite.932 If any one confesses the truths mentioned,933 but calls lawful wedlock, and the procreation of children, destruction and pollution, or deems certain kinds of food abominable, such an one has the apostate dragon dwelling within him. If any one confesses the Father, and the Son, and the Holy Ghost, and praises the creation, but calls the incarnation merely an appearance, and is ashamed of the passion, such an one has denied the faith, not less than the Jews who killed Christ. If any one confesses these things, and that God the Word did dwell in a human body, being within it as the Word, even as the soul also is in the body, because it was God that inhabited it, and not a human soul, but affirms that unlawful unions are a good thing, and places the highest happiness934 in pleasure, as does the man who is falsely called a Nicolaitan, this person can neither be a lover of God, nor a lover of Christ, but is a corrupter of his own flesh, and therefore void of the Holy Spirit, and a stranger to Christ. All such persons are but monuments and sepulchres of the dead, upon which are written only the names of dead men. Flee, therefore, the wicked devices and snares of the spirit which now worketh in the children of this world,935 lest at any time being overcome,936 ye grow weak in your love. But be ye all joined together937 with an undivided heart and a willing mind, “being of one accord and of one judgment,”938 being always of the same opinion about the same things, both when you are at ease and in danger, both in sorrow and in joy. I thank God, through Jesus Christ, that I have a good conscience in respect to you, and that no one has it in his power to boast, either privately or publicly, that I have burdened any one either in much or in little. And I wish for all among whom I have spoken, that they may not possess that for a testimony against them.