There was a second son in the parable, under whom Jesus addressed the Pharisees and the scribes to the self-righteous (Luke 18:9). This son had never left the Father's house; he had always remained close to the religious ministry, to its rules and regulations, always subject to the law. In it he worked and lived. He also now came, so to speak, from the field; he had done "field service".
Yet he is also a »lost son«, even more hopeless than his brother! Why?
He doesn't know mercy! He thinks he has to earn the love of the Father through achievement. If he had been told: "Your father does not only want to fulfill his duty, he wants your love, your heart," then he might have answered: "What is this! I have to go to the field, to the field." Others would perhaps say: "What is this? I must preach! My work is my worship!" Such a man builds on his performance; he thinks he does not need grace!
When this son notices that a feast is celebrated in the father's house for his brother who has returned, he becomes angry and does not want to go inside to rejoice with the others about the return of this silly nonsense. He does not understand what is important in heaven: not great rulers and mighty princes, but sinners who repent, the return of people to the Father's house of God so that their names may be written in heaven.
But this brother didn't want to go in the house. He did not want to hear the word grace; even today there are people who do not appreciate this word, who avoid it or even replace it. Some even express their aversion to grace with a word from the Bible: "Faith without works is dead"; they do not see that the younger son did not remain without works after he had returned; but repentance and return are not bound to previous works, but to faith and grace; the works then follow out of faith!
But the older son was not pleased with the grace; neither was he glad to have stayed with the father all the time. His reproaches to the Father show his bitterness; they show no joy for his own condition. His father came out to ask him into the house; his father's love also embraces him and asks him! But he is angry! He does not even address the Father with Father, but reproaches him for what your Son - not my brother - has done; he refers to his immoral and wasteful way of life and to his own diligence and constant willingness to perform; he refers to the fact that he has never transgressed the commandment of the Father.
Basically, he's accusing the father. He does not say like Paul: "I am the greatest of all sinners"; no, the elder son says: "You have never given me a goat"; whereas a born-again child of God accepted in grace says: "You gave me everything in Jesus!"
Also today there are people who accuse God, who also call him God, Lord God, Yahweh, Jehovah, but who barely speak the word Father, yes, who do not even speak the prayer of our Lord, the »Father of our«. They should ask themselves why! Are they returned home born again children of God? In any case, the father also asks the older son to come into the house of the family of God; Jesus asks the leaders of the Jews, he asks today the pious, self-righteous, self-reliant, who have the "right religion", all those who believe they can make claims. He who commands cherubim and seraphim, he asks!
The son, on the other hand, is not cheerful, not of good cheer; why? Because he is blocking himself against the will and intentions of the Father! He wants to assert himself in his own acquired justice, wants to be better than his brother! As some say: "I believe in the ransom of Christ, but ... one must do something, work for one's own salvation, not throw grace at everyone!"
I once heard a diligent Jehovah's Witness say about the excluded: "I have worked all my life for my faith, put everything into it, and they may come back just before Armageddon and then be saved like me, receive the same; that wouldn't be fair, just not just!". But the Father calls upon the Son in the parable: Rejoice, for one must rejoice: Your brother has come to life, has been found! See the grace of God correctly! It makes the dead alive, finds the lost!
The story does not end; Jesus leaves the conclusion open; he leaves it up to the Jewish leaders whether they want to enter the house of God's grace and rejoice with the sinners and tax collectors who have returned. History shows that they did not want to! They killed the bearer of grace.
The story is also open for us today. Again: The objection that faith without works is dead does not apply here, because it can be assumed, indeed must be assumed, that the returned Son now also produced works of faith; but only after his return! He was allowed to return as he was, and was accepted with his confession of faith in grace. He did not need any works to be allowed to return home; but love and gratitude move every child of God to works of praise of God.
That's a big difference.
The older son, as well as people who resemble him today, must decide whether they want to enter the house of grace of their father in order to rejoice with everyone who returns. Above all, however, they must realize that they also need grace, because in all the good works they may do they cannot stand before God by their own strength, not by their own righteousness, but anyone who accepts the righteousness given to us by Christ's death in faith may always be in the house of God, as God's child and member of his family. With the missing end, Jesus asks each one of us the question: How do you want to keep it now? Do you take the last step into the father's house or do you not? I wish every reader the right decision!