In 1969 Simon Wiesenthal penned his thought-provoking book, The Sunflower, which captured the agony he personally experienced in one of history’s darkest moments. Relating one encounter with the Holocaust, Wiesenthal described how he had been taken from a Nazi death-camp to a makeshift army hospital. He was ushered by a nurse to the side of a Nazi soldier who had asked to have a few private moments with a Jew. Wiesenthal warily entered the room and was brought face to face with a fatally wounded man, bandaged from head to toe. The man struggled to face him and spoke in broken words. Wiesenthal nervously endured the anxious monologue, finding himself numbed by the encounter. At the hands of Nazi soldiers like the one now dying before him, Wiesenthal had lost 89 of his own relatives. Here, the soldier confessed to the heinous act of setting ablaze an entire village of Jews; at his whim, men, women, and children were burned to death. With great anxiety, he described his inability to silence from his mind the screams of those people. Now on a deathbed himself, the man was making a last desperate attempt to seek the forgiveness of a Jew. The man begged him to stay, repeating his cry for forgiveness, but Wiesenthal could only walk away.

Yet even years later he wondered if he had done the right thing. Should he have accepted the man’s repentance and offered the forgiveness so earnestly sought? Had he neglected a weighted invitation to speak or was silence the only appropriate reply? Seeking an answer, Wiesenthal wrote to thirty-two men and women of high regard—scholars, noble laureates, psychologists, and others. Twenty-six of the thirty-two affirmed his choice to not offer the forgiveness that was sought. Six speculated on the costly, but superior, road of pardon and mercy.

I don’t know what it would take to absolve anyone of so monumental a crime. I don’t know if it is possible to offer forgiveness for something so far beyond our moral categories. But I know that even in the most unfathomable places, the God of Scripture somehow carries the burden of prodigal grace. Who can fathom the Son of God on the cross pleading with the Father to forgive the guilty for killing him? Who can conceive of a God who comes among his people, trusting himself to the hands of a fallen world, even knowing the troubling outcome? Who can grasp the heart of a God who chooses to love an undeserving people? To live as one marked by this disruptive grace is not easy. It is easier to forget that the command to forgive is thoroughly unsettling; in fact, sometimes haunting. To persist in love when we are tired or overwhelmed, or even rightfully angered by injustice, is a massive and costly request.

I have often found it easier to fit into shoes of the prodigal son than the shoes of the remaining older brother.  Yet in this well-known parable of Jesus, both sons are invited to celebrate and rejoice. To the prodigal child who has squandered and defamed, God’s grace is lavish. It is extravagant and poured out on those who neither expect it nor deserve it. The celebration is thrown in the honor of the run-away, in honor of the return of just one lost sheep. When these shoes are ours, we are both humbled by the Father’s attention and compelled by God’s mercy.

Yet to the child on the other side of justice, the Father’s grace is jarring and disruptive. It is lavish, but wastefully so. His invitation to the feast is both awkward and demanding, a seeming call to overlook the potential of our reckless brother to strike again at our expense. These shoes are much harder to walk in. The Father’s call to forgive the one whose sincerity is questionable is often agonizing; his command to love the habitual prodigals in our midst is both costly and exhausting.

But it is Christ’s request. “Lord, how many times shall I forgive my brother when he sins against me? Up to seven times?” asked Peter. But Jesus answered, “I tell you, not seven times, but seventy times seven” (Matthew 18:21-22).  God’s grace disrupts our sense of righteousness and summons us to respond in similar kind. Whether we find ourselves in the shoes of the prodigal or treading the difficult ground of the older brother there is good reason to rejoice and celebrate the unveiling love of the Father. God’s unfathomable grace and mercy shatters our sense of who is worthy to enjoy the benefits of God’s kingdom, inviting us to the celebration regardless of where, and in whose shoes, we stand.

Jill Carattini is managing editor of A Slice of Infinity at Ravi Zacharias International Ministries in Atlanta, Georgia.