Ignatius - Preaching Christ

But if any one preach the Jewish law 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 of this world, lest at any time being conquered by his artifices, ye grow weak in your love.

But to me Jesus Christ is in the place of all that is ancient: His cross, and death, and resurrection, and the faith which is by Him, are undefiled monuments of antiquity; by which I desire, through your prayers, to be justified. - Ignatius

Alexander Roberts, James Donaldson, and A. Cleveland Coxe, eds., The Apostolic Fathers With Justin Martyr and Irenaeus (ANF I; Accordance electronic ed. 9 vols.; New York: Christian Literature Company, 1885), n.p.

The Mosaic Law

To those under the law I became as one under the law (though not being myself under the law) that I might win those under the law.  21 To those outside the law I became as one outside the law (not being outside the law of God but under the law of Christ) that I might win those outside the law. - 1 Cor. 9, ESV

What clues are we given that we can put a prohibition against murder into the category of a “moral” issue while putting fasting or the Sabbath into a different category? VanGemeren’s own approach here suggests, rather, that Jesus treated them all together as part of the single entity—the Mosaic law. Perhaps VanGemeren would reply at this point that Jesus’ own treatment of the different commandments reveals just such a distinction. He absolves his followers from obeying the ceremonial law, while he reiterates and sharpens the moral laws. But this is just my point. It is only as we look at the way that Jesus and the writers of the New Testament treat the commandments of the Mosaic law that we can know which ones continue to apply directly to us and which ones no longer do. The Mosaic commandments, then, are not directly applicable to us, but only as they are passed on to us by Christ. He is the “filter” through which the whole law must go, and it is he who determines which of those laws must still be followed and which ones need not be.

Bahnsen, Greg L.; Kaiser, Jr., Walter C.; Moo, Douglas  J.; Strickland, Wayne G.; VanGemeren, Willem A. (2010-09-21). Five Views on Law and Gospel (Counterpoints: Bible and Theology) (pp. 87-88). Zondervan. Kindle Edition.