john Piper explains that the cross was the answer to an essential problem- the problem of how God can simply overlook sin: “God’s righteousness is at stake. His name or reputation or honor must be vindicated. Before the cross can be for our sake, it must be for God’s sake.”. Piper uses the example of David as why this problem exists.
David feels the rebuke of Nathan, and in verse 13 he says, “I have sinned against the LORD.” To this, Nathan responds, “The LORD also has put away your sin; you shall not die.” Just like that! Adultery and murder are “passed over.” It is almost incredible. Our sense of justice screams out, “No! You can’t just let it go like that. He deserves to die or be imprisoned for life!” But Nathan does not say that. He says, “The LORD has put away your sin; you shall not die.”
Would the relatives of Uriah the Hittite have been happy at the notion of Davids sin going unpunished? If your son had been killed, surely you would expect the killer to be punished. God simply passes over the sin- he “puts it away”. But where does he put it away to? So why does Jesus die?
God saw his glory being despised by sinners (like David) he saw his worth belittled and his name dishonored by our sins and rather than vindicating the worth of his glory by slaying his people, he vindicated his glory by slaying his Son.
God could have settled accounts by punishing all sinners with hell. This would have demonstrated that he does not minimize our falling short of his glory our belittling his honor. But God did not will to destroy. “Indeed God did not send the Son into the world to condemn the world, but in order that the world through him might be saved” (John 3:17).