"Good works are bad and are sin like the rest" [Denifle’s Luther et Lutheranisme, Etude Faite d’apres les sources. Translation by J. Paquier (Paris, A. Picard, 1912-13), VOl. III, pg. 47].
In my earlier entry I hadn't yet had a copy of Denifle’s Luther et Lutheranisme Volume 3. Luther et Lutheranisme III is now available. Page 47 can be found here. The section in question appears to be the following:
According to a rough translation via Google, the last sentence says something like, "Good works themselves are unjust: they are sins." The statement is actually a summary by Denifle of Luther. Footnote 3 refers to this page from this source. This source is Johannes Ficker's publication of Luther's Lectures on Romans. The text reads as follows:
The pertinent section of text says in English,
From all of this it is obvious that there is no sin which is venial according to its substance and its nature, but also no merit. For even the good works which are done while the tinder of sin and sensuality are fighting against them are not of such intensity and purity as the Law requires, since they are not done with all of our strength, but only with the spiritual powers which struggle against the powers of the flesh. Thus we sin even when we do good, unless God through Christ covers this imperfection and does not impute it to us. Thus it becomes a venial sin through the mercy of God, who does not impute it for the sake of faith and the plea in behalf of this imperfection for the sake of Christ. Therefore, he who thinks that he ought to be regarded as righteous because of his works is very foolish, since if they were offered as a sacrifice to the judgment of God, they still would be found to be sins. As Ps. 36:2 says, “For he has acted deceitfully in His sight, so that his iniquity is found to be for wrath,” that is, before God and within his own spirit there was deceit and not the truth of righteousness, even though before men he makes a display of righteousness in his works. For he could not be righteous within himself without the mercy of God, since he is corrupt because of the tinder of sin. Therefore iniquity will be found in his righteousness, that is, even his good works will be unrighteous and sinful. This iniquity will not be found in believers and those who cry to Him, because Christ has brought them aid from the fullness of his purity and has hidden this imperfection of theirs. For they seek also this and hope for it from Him, but the others do not seek it but presumptuously think they have it.[LW 25:275].This comment comes from Luther's pre-Reformation writing. Luther says, "we sin even when we do good, unless God through Christ covers this imperfection and does not impute it to us." It then becomes a "venial sin" "through the mercy of God, who does not impute it for the sake of faith and the plea in behalf of this imperfection for the sake of Christ." Someone who claimed to be righteous because of his works fails. That is, no one can be righteous without Christ.
The quote in question was actually Luther's view summarized by Denifle. Denifle wrote in German, his book was then translated into French. The French version of Denifle was then used by Antonin Eymieu who translated a snippet from Denifle back into English, and then Luther, Exposing the Myth took the quote. I enjoy looking up these quotes because one never knows what one will find. Luther, Exposing the Myth portrays Luther as an antinomian against good works. This context though says something quite different.