Justice is something we typically want for others; mercy is something we typically want for ourselves. If you’re married, you probably see this played out on a daily basis. When faced with your spouse’s shortcomings—sometimes as simple as an unfinished task—the “law” comes out. “The dishes aren’t done,” you might insist, or, “the lawn needs mowed.” But when the shoe’s on the other foot, you expect leniency. A friend of mine told me that he’d come to realize that “law for you, grace for me” had become one of the defining features of his marriage. And it hurt.
Earlier this week we’ve observed that God gives blessings to his people, and we’ve also seen that it’s only natural for us to desire justice for wrongdoing. How these two traits fit together is a thing of beauty, so much so that it’s been sung even in the ancient worship songs of Israel:
Steadfast love and faithfulness meet;
righteousness and peace kiss each other.
11 Faithfulness springs up from the ground,
and righteousness looks down from the sky.
12 Yes, the Lord will give what is good,
and our land will yield its increase.
13 Righteousness will go before him
and make his footsteps a way. (Psalm 85:10-13)
The unnamed writer tells us that “righteousness and peace kiss each other.” This same righteousness that demands justice for sin is unified with the peace of God’s salvation.
Nowhere do we find that more clearly demonstrated than in the cross itself, where God’s love and God’s fierce justice intersect on a hillside just outside the city.
John Stott writes:
“It is the Judge himself who in holy love assumed the role of innocent victim, for in and through the person of his Son he himself bore the penalty that he himself inflicted. As Dale put it, “The mysterious unity of the Father and the Son rendered it possible for God at once to endure and to inflict penal suffering.” There is neither harsh injustice nor unprincipled love nor Christological heresy in that; there is only unfathomable mercy. For in order to save us in such a way as to satisfy himself, God through Christ substituted himself for us. Divine love triumphed over divine wrath by divine self-sacrifice. The cross was an act simultaneously of punishment and amnesty, severity and grace, justice and mercy.”
At the cross we find both mercy and justice. Justice, because Jesus paid the debt of human wickedness, and mercy, because this payment wipes our slates clean. We therefore are released from the weight of our own shame, but we are also released from the weight of our social outrage. That is, when we are confronted with radical evil—whether in the headlines or our own households—we look to the cross and recognize that true justice is found there, that when we demand blood God offers his own.
No matter the headline, no matter the circumstance, justice is ultimately found in the righteousness of God. And so is mercy. I don’t mean to say that there are no earthly consequences—as if God does not use such events even to discipline his own children. But as Christians we extend mercy and grace to our brothers and sisters knowing their debts have been paid the same as ours.
 John Stott, The Cross of Christ, 158-9.