The Epistles of Ignatius

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 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 profess Christ Jesus, and to Judaize. For Christianity did not embrace Judaism, but Judaism Christianity, that so every tongue which believeth might be gathered together to God.