5. It becomes more evident that love is transformed into mercy when it is necessary to go beyond the precise norm of justice-precise and often too narrow. The prodigal son, having wasted the property he received from his father, deserves - after his return - to earn his living by working in his father's house as a hired servant and possibly, little by little, to build up a certain provision of material goods, though perhaps never as much as the amount he had squandered. This would be demanded by the order of justice, especially as the son had not only squandered the part of the inheritance belonging to him but had also hurt and offended his father by his whole conduct. Since this conduct had in his own eyes deprived him of his dignity as a son, it could not be a matter of indifference to his father. It was bound to make him suffer. It was also bound to implicate him in some way. And yet, after all, it was his own son who was involved, and such a relationship could never be altered or destroyed by any sort of behavior. The prodigal son is aware of this and it is precisely this awareness that shows him clearly the dignity which he has lost and which makes him honestly evaluate the position that he could still expect in his father's house. 

6. Particular Concentration on Human Dignity 

This exact picture of the prodigal son's state of mind enables us to understand exactly what the mercy of God consists in. There is no doubt that in this simple but penetrating analogy the figure of the father reveals to us God as Father. The conduct of the father in the parable and his whole behavior, which manifests his internal attitude, enables us to rediscover the individual threads of the Old Testament vision of mercy in a synthesis which is totally new, full of simplicity and depth. The father of the prodigal son is faithful to his fatherhood, faithful to the love that he had always lavished on his son. This fidelity is expressed in the parable not only by his immediate readiness to welcome him home when he returns after having squandered his inheritance; it is expressed even more fully by that joy, that merrymaking for the squanderer after his return, merrymaking which is so generous that it provokes the opposition and hatred of the elder brother, who had never gone far away from his father and had never abandoned the home. 

The father's fidelity to himself - a trait already known by the Old Testament term hesed - is at the same time expressed in a manner particularly charged with affection. We read, in fact, that when the father saw the prodigal son returning home "he had compassion, ran to meet him, threw his arms around his neck and kissed him."64 He certainly does this under the influence of a deep affection, and this also explains his generosity towards his son, that generosity which so angers the elder son. Nevertheless, the causes of this emotion are to be sought at a deeper level. Notice, the father is aware that a fundamental good has been saved: the good of his son's humanity. Although the son has squandered the inheritance, nevertheless his humanity is saved. Indeed, it has been, in a way, found again. The father's words to the elder son reveal this: "It was fitting to make merry and be glad, for this your brother was dead and is alive; he was lost and is found."65 In the same chapter fifteen of Luke's Gospel, we read the parable of the sheep that was found66 and then the parable of the coin that was found.67 Each time there is an emphasis on the same joy that is present in the case of the prodigal son. The father's fidelity to himself is totally concentrated upon the humanity of the lost son, upon his dignity. This explains above all his joyous emotion at the moment of the son's return home. 

Going on, one can therefore say that the love for the son the love that springs from the very essence of fatherhood, in a way obliges the father to be concerned about his son's dignity. This concern is the measure of his love, the love of which Saint Paul was to write: "Love is patient and kind.. .love does not insist on its own way; it is not irritable or resentful...but rejoices in the right...hopes all things, endures all things" and "love never ends."68 Mercy - as Christ has presented it in the parable of the prodigal son - has the interior form of the love that in the New Testament is called agape. This love is able to reach down to every prodigal son, to every human misery, and above all to every form of moral misery, to sin. When this happens, the person who is the object of mercy does not feel humiliated, but rather found again and "restored to value." The father first and foremost expresses to him his joy that he has been "found again" and that he has "returned to life. This joy indicates a good that has remained intact: even if he is a prodigal, a son does not cease to be truly his father's son; it also indicates a good that has been found again, which in the case of the prodigal son was his return to the truth about himself.

[Pope John Paul II, Dives in Misericordia]