The Contrary Death

God has done what the law, weakened by the flesh, could not do. By sending His own Son in the likeness of sinful flesh and for sin, He condemned sin in the flesh.
ROMANS 8:3
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The Contrary Death
Whenever I feel remorse in my conscience on account of sin, therefore, I look at the bronze serpent, Christ on the cross (John 3:14-15). Against my sin, which accuses and devours me, I find there another sin. But this other sin, namely, that which is in the flesh of Christ, takes away the sin of the world. It is omnipotent, and it damns and devours my sin. Lest my sin accuse and damn me, it is itself damned by sin, that is, by Christ the crucified, "who for our sake was made to be sin, so that in Him we might become the righteousness of God" (2 Corinthians 5:21). Thus in my flesh I find a death that afflicts and kills me; but I also have a contrary death, which is the death of my death and which crucifies and devours my death.

From Lectures on Galatians (1535) (Luther's Works 26:159-60)