When law and gospel collide the immovable mass meets the unstoppable force. God's law is implacable. We deserve to be devastated by its judgments. We bear within ourselves the just cause for our own impeachment before God. God is right in accusing us of our depravity. He is just in condemning all those who transgress His law. We all feel this instinctively. We have had the opinion of the law sewn into our fallen hearts. We all want to excuse ourselves for our wickedness or we want to accuse someone else of our same sin, so that we look better by comparison. It is a natural sense to feel the burden of our own wickedness in that sinking feeling that we stand before God exposed and naked under the bolts of His just judgment. "Enter not into judgment with your servant, for no one living is righteous before you" (Ps 143:2). We cry to the hills, "cover us!" and to the mountains "fall on us!" rather than face this judgment (Lk 23:30). The weight of the world is lighter than the burden of the accusing and condemning word of a just God. Certainly Jonathan Edwards was entirely half right in his sermon "Sinners in the Hands of an Angry God."

How then will we survive in the sight of such a just God? How can David so boldly ask, "Have mercy on me, O God"? On what basis could he possibly make such request? He was to be and act right. He failed dismally. There was no basis in him that such a request could be honored. It was as though he were insulting the Ten Commandments and the just God who gave them. The plea for mercy is a clear confession of transgression. It is a bit like the small boy who appears shamefaced before his father and first of all says, "Please don't spank me..." The plea for mercy is a prelude to the confession of some transgression that demands his father's wrath. He knows what He justly deserves for His crime. Everyone knows this in his heart of hearts.

What great courage it takes to face down this accusation and simply apply to God for His mercy. David had every reason to expect nothing but judgment at the hands of an angry God (2Sa 12:13). Instead, he believed that God would have mercy on him though he was a poor sinner conceived in sin (Ps 51:5). He had to face down the accusation of the preacher, Nathan, the blame of the entire royal court, the death of his child, and the mockery of God's enemies. All this should have driven David to the madness that calls down the weight of the world to crush him into extinction. But quietly he calls for mercy. What is the weight that he can count on to countervail against the law and its righteous accusation? 

This is the countervailing weight of the mercy of God. Only God can provide it. Who or what creature could ever provide the power to push back the accusation of the just God's law? None. Only the God who desires not only to be counted just but also to be the One who justifies sinners can move that burden of the law. He does it by lashing it to the shoulders of His own precious Son, driving it into His pierced hands, and crushing it into His precious skull. Only the countervailing weight of God's Son will suffice to take away David's sin and ours. On that basis alone can we make the plea: "Have mercy on me!" We must be blind and deaf to the law. We must plead the Son of God. In Him we have become Sinners in the Hands of a Gracious God.

Martin Luther