The purpose of the parable isn’t to teach us that God will always welcome us home or to be a joyful rule follower. Rather, the heart of the parable, and indeed the very heart of the Gospel, is to teach us what it means to become the Father.
Is repentance and reconciliation within the contemplation of the younger son? Does he anticipate any change in his relationship with the father? At this point in the story, has the younger son learned anything from his experience? Do you agree with Fr. Nouwen that Jesus himself can be seen as the younger son?