The Prodigal Son – the "obedient son"

I have really procrastinated following up on the prodigal son story. Mostly because I feel somewhat inadequate sharing and posting. There have been books written about this chapter and I am not sure how to make it concise enough. I'm going to give it a try but if this wet your appetite there is a book written called the "Prodigal God" by Timothy Keller.
The 3rd main character is the elder son and one who considers himself to be the obedient son and from our point of view he is. We would look at him and say he is an upstanding citizen. Some of the things he says though reveal what's in his heart. I'm not sure where in the Bible it is but there is a verse that says that "man looks on the outward appearance but God looks at the heart. The "obedient son" actions and speech let us into a little bit of what he really thinks.
He tells his loving father that that he has served faithfully for many years. It's obvious from his attitude and desire to grasp the heart of the father. The heart of the father longs for companionship with his sons and views the return of the prodigal is a great thing. The obedient brother does not see it that way. He is angry at the father because he has rejoiced that the prodigal returned. Is anger and attitude of not going in the celebration shows how little he grasps the father's heart. This "obedient son" looks at his years of faithful service not as serving the father but somehow using it as a lever to force the father to appreciate him. When we look at this from God's point of view we have to say that is missing the point. If we were to spend our entire lives never breaking any of God's principles we would still have to say all we have done is what we are supposed to do. There is no forcing God to accept us because we think were good enough. Roman says all have sinned and come short of the glory of God. One principle the obedient son thinks is that the father is now a debtor to him. We have to remember that God will not be debtor to any man and cannot be. He. Is our Creator and we is owed everything. One other thing the oldest son says is that the father ever killed the fattened calf so he could celebrate with his friends. This may be somewhat subtle but lets us in on his attitude. He didn't want to celebrate with the father but wanted to celebrate with his friends. He exaggerates the failings of the prodigal based on what we are told earlier. There is no mention of spending his money on harlots it that is where the obedient son takes the discussion. Either he knows more about the situation then he is letting on or he is exaggerating the failings of the prodigal.
So from the outward as we see these son who is always there and he says enough to the father to make us realize that he does not understand the fathers heart of love. The father's heart overflows toward the prodigal because "he was dead but now he's alive". Jesus said he came to save sinners. In Luke 15 also mentions that there is joy in heaven among the Angels over one sinner that repents. When my favorite hymns says:
softly and tenderly Jesus is calling calling for you and for me.... Oh sinner, home!