Please feel free to share your thoughts in the Discussion Forum. While Luther was a man of great importance and influence, not every thing Luther said, thought, or wrote is inspired by God. This treatise is definitely not from God, nor is it consistent with what God's Word says. Error needs to be pointed out where it exists--even if the error is made by an influential person.
The following is a verbatim reproduction of part of Dr. Martin Luther's treatise entitled On the Jews and Their Lies. It's source on the Internet is The Internet Medieval Sourcebook. Please note that the text is part of the public domain.
The other boast and nobility over which the Jews gloat and because of which they haughtily and vainly despise all mankind is their circumcision, which they received from Abraham. My God, what we Gentiles have to put up with in their synagogues, prayers, songs, and doctrines! What a stench we poor people are in their nostrils because we are not circumcised! Indeed, God himself must again submit to miserable torment if I may put it thus as they confront him with inexpressible presumption, and boast: "Praised be Thou, King of the world, who singled us out from all the nations and sanctified us by the covenant of circumcision!" And similarly with many other words, the tenor of all of which is that God should esteem them above an the rest of the world because they in compliance with his decree are circumcised, and that he should condemn all other people, just as they do and wish to do.
In this boast of nobility they glory as much as they do in their physical birth. Consequently I believe that if Moses himself would appear together with Elijah and their Messiah and would try to deprive them of this boast or forbid such prayers and doctrine, they would probably consider all three of them to be the three worst devils in hell, and they would be at a loss to know how to curse and damn them adequately, to say nothing of believing them. For they have decided among themselves that Moses, together with Elijah and the Messiah, should endorse circumcision, yes, rather that they should help to strengthen and praise such arrogance and pride in circumcision, that these should, like themselves, look upon all Gentiles as awful filth and stench because they are not circumcised. Moses, Elijah, and the Messiah must do all that they prescribe, think, and wish. They insist that they are right, and if God himself were to do other than they think, he would be in the wrong.