He stands for the self-righteous Pharisee's who would rather see a sinner destroyed than saved. Certain things stand out about him.
(i) His attitude shows that his years of obedience to his father had been years of grim duty and not of loving service.
(ii) His attitude is one of utter lack of sympathy. He refers to the prodigal, not as any brother, but as your son. He was the kind of self-righteous character who would cheerfully have kicked a man farther into the gutter when he was already down.
(iii) He had a peculiarly nasty mind. There is no mention of harlots until he mentions them. He, no doubt, suspected his brother of the sins he himself would have liked to commit.
The Father searches for the lost son on the horizon, the father represents God (Abba), The lost prodigal represents the sinner (you and me)
The Lost comes running to the father because we have free will (choose life eternal, or not) The elder son is ungrateful of the blessings of the Father, he is judgemental, narrow minded, unloving, and uncaring,
instead of running to his brother in wild and loving abandonment he accuses and whines in petty greed and jealously.
the younger son while being lost, found the Holy spirit by confession of his sin, his poverty and filth brought on the conviction of his sin and it convinced him of his fathers rightousness.
The eldest son lost the presence of the holy spirit when he turned a blind eye to love and forgiveness.
When we are convicted of our sin and convinced of gods rightousness by the power of the holy spirit, (geist=Ghost=Spirit), we find the natural outcome is love and forgiveness (love all, worship one).
By losing his love and compassion the elder son (i.e. the pharisee's and the sadducees that made up the council of the sanhedren had lost the holy Spirit!
The ultimate sin, is sin against the holy spirit!
Romans 10:14 says "How then shall they call on him in whom they have not believed? and how shall they believe in him of whom they have not heard? and how shall they hear without a preacher"?
Preach the word, be instant in season, out of season, reprove, rebuke with all longsuffering; for the time will come when they will not listen to sound doctrine!