Our faith is rooted in the ability of people to change their value systems.
The Pauline disciple responsible for I Timothy perfectly sums up the Christian situation: ''Christ Jesus came into the world to save sinners. Of these, I am the foremost." Those committed to becoming other Christs are not only expected to go through constant periods of repentance, they're also expected to encourage and rejoice over that same repentance in others.
This obviously is the reason Luke's Jesus tells three parables about finding the "lost" in today's gospel pericope. The first two - the lost sheep and coin - are generic enough that most in the evangelist's community can nod and say, "Yep! That makes sense." But the third is so concrete that it must have created some problems. When it comes to actually welcoming a specific, lost person back into the community, we might have to stop and talk about it. It has a lot of challenging implications.
Of course, the "prodigal" person in the story isn't the younger son; it's the father. He goes completely overboard in receiving his wasteful son back into his good graces. So overboard that the older son instinctively starts to calculate what his father's generosity is costing him.
Once the boy demanded his father give him his half of the inheritance, the remainder of the inheritance belonged to his brother. That means the finest robe and ring his father had so quickly bestowed on this recently returned scoundrel was actually his, not to mention the fatted calf that was being quickly devoured. His father's only excuse for giving away part of his inheritance was a simple, "... Your brother was dead and has come to life again; he was lost and has been found."
I presume Luke was aware of some resentment in his gospel community over how easily and generously it reinstated repentant sinners. We don't have that exact problem today. Once the "confessional" stipulations with which we're all familiar came into existence, the sinner is expected to go through specific institutional hoops before we kill the fatted calf. It makes us good folk feel a little better to know that we who've never left the farm have an easier, less complicated path to salvation.
Scripture scholars frequently remind us that the triggering device for today's Exodus golden calf passage wasn't the behavior of recently freed slaves in the Sinai during their 13th century BCE exodus. Rather it was the behavior of 8th century BCE Israelites toward the cherub statues set up in their Yahweh shrines. These mythological creatures usually sported the body of a bull, the wings of an eagle and the head of a human. (The well-known Egyptian Sphinx is a variant, having a lion's body.) It was believed that the gods employed them for transportation and enthronement. Priests put them in Jewish shrines (and on the top of the Ark of the Covenant) to assure the faithful that Yahweh was really present in those places. The problem is that, after a while, some people thought these "bulls" actually were Yahweh, and began to worship them, believing the "calf," not Yahweh, had brought them out of Egypt.
Each of today's three sacred authors is insistent that we cut through the "institutional accretions" that are part of any organized religion, and return to the basics of faith. Yahweh's offer of freedom is at the center of Jewish faith; Jesus' offer of forgiveness is at the center of Christian faith. Any cries of "injustice" by those who don't think they need to repent is simply a sign they should be the first sinners in line to receive God and the church's forgiveness.