The Way of the Cross V: Heidelberg Disputation, Thesis V

Martin Luther

Thesis 5.
The works of men are thus not mortal sins (we speak of works which are apparently good), as though they were crimes

“For crimes are such acts which can also be condemned before men, such as adultery, theft, homicide, slander, etc. Mortal sins, on the other hand, are those which seem good yet are essentially fruits of a bad root and a bad tree. Augustine states this in the fourth book of ‘Against Julian’ (Contra Julianum)”. (LW 31, 45)

Like thesis 3 and 4, thesis 5 and 6 are also parallel and contrasting assertions. They are here to pinpoint and bring the sinfulness of humans more clearly to light, by the light of the cross. While thesis 5 focuses on the good works that humans do in their own power, thesis 6 deals with the works that God does in us.

Let’s first talk about thesis 5. The fifth thesis expands on the third thesis. Luther, in the third thesis said, “The attractive and good works of man are to be mortal sins.” He expands on this topic in thesis 5. In other words, the works of man, which are mortal, are not mortal sins in the sense that they are crimes such as adultery, theft, homicide, slander, etc. as Luther mentioned in the proofreading.

Then, why are the attractive and good works of man mortal sins if they are not crimes?

The works of man appear to be morally good and beneficial. This apparent goodness of our works seduces us into placing our trust in our self, rather than in God. Luther affirms that the works of man, which seem to be apparent goodness, are mortal sins because they stem from fruits that come from a bad root.

To support his claims, Luther mentioned Augustine. In the fourth book of, “Against Julian”(Contra Julianum), Augustine states that there is no goodness without God’s grace given to us through His Son, Jesus Christ.

“Realize we say that this good of men, this good will, this good work can be conferred on no one without the grace of God which is given through the one Mediator of God and men, … All other works which seem praiseworthy among men may seem to you to be true virtues and they may seem to be good works and to be carried out without any sin, … You call these wills good trees; it suffices for me that they are barren with God and therefore not good.” (Augustine, Contra Julianum , Bk. IV, Ch. 33)

Luther here points to a deepening of the concept of mortal or deadly sin. A deadly sin is one that actually separates and seals us off from God. That occurs when the apparent goodness of our works seduces us into putting our trust in that occurs when the very goodness of the work is such that it dissuades us from confessing. Then, human beings become reliant upon their own righteousness, not on the absolute grace of God.

In his Lecture on Romans, Luther raised the following question: “For who can be a recipient of grace and righteousness unless he confesses that he is a sinner?” (“Luther: Lecture on Romans” in the Library of Christian Classics, p. 78)

Luther states that the only man who confesses his sins before God can glorify God: “For he who humbly puts all righteousness away from himself and confesses himself a sinner before God thus glorifies God who alone is righteous”(above book, pp. 66-67)

Today, the theology and churches in Korea puts too much emphasis on ‘the social responsibility of Christians’, and ‘the holy life’ as part of an effort to reform the church and society. But I have to say that those efforts to live as good Christian easily lead us to rely on our works and dissuades us from confessing. As Luther pointed out, we must seriously ponder the idea “that it is not enough to confess with one’s mouth that one is sinful, unrighteous, untruthful, or foolish.”(above book, p. 81)

Thesis 5 tells us that even though the works of man appear to be morally good and beneficial, this apparent goodness of our works seduces us into placing our trust in self rather than God. Therefore, Luther said: “For we must continuously accuse, judge, and condemn ourselves and confess ourselves as evil in order that God may be justified in us” (above book, p. 81)

Pastor Jin O Jeong 2
(Photo : Pastor Jin O Jeong)

Reverend and Doctor Jin O Jeong is an assistant pastor for the Korean congregation at Zion Lutheran Church, Belleville, IL. He graduated from Luther University and received a Ph.D from Yonsei University. He was also a Research Fellow at Hebrew University and Visiting Scholar at Yale Divinity School. Tel: 618-920-9311 Email :

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