Today, I liked this quote. I am not sure where the sermon might be online. So I'm typing. Volume 51, p. 284, Luther's Works. I like it because Luther makes it very clear in this first sentence that pure doctrine must distinguish between justification before God, versus before men, and how similarly faith and love, and life toward God and toward man should not be mixed up. He also explains how very difficult this is for our nature and in opposition to false teaching, to have faith in the one Mediator and cling to the mercy seat. The whole sermon is an excellent exposition of faith and love, based on the verses 1st Timothy 1 (5-7) "The aim of our charge is love that issues from a pure heart and a good conscience and sincere faith. Certain persons by swerving from these have wandered away into vain discussion, desiring to be teachers of the law, without understanding either what they are saying or the things about which they make assertions."
This, then, is the right, pure doctrine, which should be cultivated and in which the people should be instructed so they can tell how they are to be justified both before God and before men, and so that they will not interchange and mix up faith and love or life toward God and life toward men. This is what those vainglorious preachers should be doing, since they want to be regarded as masters of the law, in order that it may be well known and observed in Christendom. For even when it is taught in the best possible way it is difficult enough to learn it well, expecially for us, who have been so habituated and trained in the doctrine of works and pointed only to the law and ourselves. And besides this add our own nature, which is itself inclined in this direction. It is thus so rooted and strengthened by habit and the heart so strongly influenced that we cannot get away from it or think anything except that, if I have lived a holy life and done many great works, God will be gracious to me. Thus we must contend both with our nature and with strong habit. And it will be exceedingly difficult to get into another habit of thinking in which we clearly separate faith and love for the muck still sticks and clings to us, even though we are now in faith, so that the heart is always ready to boast of itself before God and say: After all, I have preached so long and lived so well and done so much, surely he will take this into account. We even want ot haggle with God to make him regard our life and for our sake turn his judgment seat into a mercy seat. But it cannot be done. With men you may boast: I have done the best I could toward everyone, and if anything is lacking I will still try to make recompense. But when you come before God, leave all that boasting at home and remember to appeal from justice to grace.
Let anybody try this and he will see and experience how exceedingly hard and bitter a thing it is for a man, who all his life has been mired in his work righteousness, to pull himself out of it and with all his heart rise up through faith in this one Mediator. I myself have now been preaching and cultivating it through reading and writing for almost twenty years and still I feel the old clinging dirt of wanting to deal so with God that I may contribute something, so that he will have to give me his grace in exchange for my holiness. And still I cannot get it into my head that I should surrender myself completely to sheer grace; yet this is what I should and must do. The mercy seat alone must prevail and remain, because he himself has established it; otherwise no man can come before God.
On page 282 we also had a nice summary:
I say that, if we are ever to stand before god with a right and uncolored faith, we must come to the point where we learn clearly to distinguish and separate between ourselves, our life, and Christ the mercy seat. but he who will not do this, but immediately runs headlong to the judgment seat, will find it all right and get a good knock on the head. I have been there myself and was so burnt that I was glad I was able to come to the mercy seat. And now i am compelled to say: Even though I may have lived a good life before men, let everything I have done or failed to do remain there under the judgment seat as God sees fit, but, as for me, I know of no other comfort, help, or counsel for my salvation except that Christ is my mercy seat, who did no sin or evil and both died and rose again for me, and now sits at the right hand of the Father and takes me to himself under his shadow and protection, so that I need have no doubt that through him I am safe before God from all wrath and terror. Thus faith remains pure and unalloyed, because then it makes no pretensions and seeks no glory or comfort save in the Lord Christ alone.