What is the whole papacy but a beautiful false front and a deceptively glittering holiness under which the wretched devil lies in hiding? The devil always desires to imitate God in this way. He cannot bear to observe God speaking. If he cannot prevent it or hinder God’s Word by force, he opposes it with a semblance of piety, takes the very words God had spoken and so twist them as to peddle his lies and poison under their name. (What Luther Says, II: 10007)

The negotiation about doctrinal agreement displeases me altogether, for this is utterly impossible unless the pope has his papacy abolished. Therefore avoid and flee those who seek the middle of the road. Think of me after I am dead and such middle-of-the-road men arise, for nothing good will come of it. There can be no compromise. (What Luther Says, II: 1019) (Online source)

Martin Luther