All these comments are fascinating but my thoughts have been trending another way lately. The Prodigal received forgiveness and grace - his initial thought was that if he confessed his sin he would get something to eat.
But the Father forgives and blesses him before he can get the words out - the robe covers his guilt, dirt and shame, the shoes show he is no longer a slave (slaves were not allowed shoes to keep them from running off), and the ring was the authority of the family name given to him.
The older son sought to gain grace and approval (and a goat to cook) through hard work. I think many of us as Christians begin to question why our (material) prayers aren't answered and two of the answers we come up with are that we aren't doing enough "good stuff" (older son) or that we are sinners (prodigal son).
The Father's reply fascinates me [paraphrase] "Son (child) you are always with me and all mine is thine." In other words, as a child of the Father everything the father had was available to the older son in the same fashion as forgiveness was available to the prodigal -- without doing anything, without "deserving" it. "Here it is; it's yours. Partake of all that I have," says the Father.
I'm beginning to work on an article that I'm tentatively calling "the Spirituality of Abundance". While I fully realize that, in this life, we are not to be controlled by money, is it wrong to participate in the Father's abundance? Not according to the Father's own words.
Neither the Prodigal's sin nor the older son's hard work and obedience seemed to matter to the Father when it came to participating in the Father's abundance.
Think this through in steps: 1) in John's letters it says "see how God has lavished his love on us that we should be called Children of God. Beloved, NOW we are Children of God." 2) In Psalms it says "the earth is the Lord's and ALL it contains" and 3) the Father said to BOTH his sons (one in actions and the other in words) "All that is mine is thine". The conclusion is that the riches of the earth are my Father's and therefore MINE.
So why did the older son seem unable to participate in this abundance? Look at his complaints -- "you never once GAVE me an animal so I could have a party with my friends" -- but how did the Father give abundance to the Prodigal?
He commanded his servants "Quick! Bring . . ." -- Hebrews says that angels are ministering spirits sent to serve those who will inherit the kingdom. I believe the older son did not participate because he kept waiting for someone to give him something. I think all he had to do was reach out and take what he wanted; the Father seemed to assume that was how things worked!
How much are we missing in life because we do not take hold of the abundance of God our Father -- not because we get a prize for being a repentant sinner nor because we have worked hard and feel we've earned something -- but simply as Children of a kind, gracious and loving (and wealthy!) Father?