Imagine a man coming home to his wife and saying, "Honey, we have been married a long time, and I have been faithful to you all these years. Now, I think I've earned the right to cheat on you and have an affair."
How do you think the wife would take that? Do you think she'd agree that he had a right to cheat on her because he'd been a good husband for so long? What would she think about his commitment to their marriage?
Imagine, on the other hand, a man coming home to his wife in tears. They also have been married a long time, but he hasn't always been faithful. He tells her that he wants to change, that he wants to work at having a strong marriage. He asks her to forgive him and to take him back.
Which man do you think got a better reception from his wife? Which marriage do you think had the better chance of surviving?
In the first reading from the prophet Ezechiel, God is describing much the same situation. The man who has been good all his life and then decides to fall into sin will die because of it. And, the man who has lived an evil life and then decides to change will save his life. The good man cannot count on all his past deeds to save him when he sins. Neither will the sins of an evil man weigh him down when he approaches God for mercy and forgiveness.
To look at an example from our own lives, we can say to ourselves, "I have gone to so many Masses in my life, it's okay if I miss Mass this one time." Or we could just as easily say, "I have missed so many Masses, I could never start to go back now." None of us has been so good in our lives that we can afford to cheat on God by sinning. On the other hand, none of us has been so evil that we cannot change our ways and turn to God for mercy. God, more than anything else, wants to save us - both the good and the bad alike. We, for our part, must seek his will every day of our lives. Like a marriage, we must renew our commitment to God daily. Each day, we must be striving for holiness.
It is often said that in the life of faith there are no plateaus. We are either going forward or sliding back. We never get to a point at which we can just take it easy and coast. Rather, we must always strive to be faithful to Jesus and to his word. We can never say that we have done enough. We can never take a vacation from our vocation to live a holy life and be a light to others. Neither can we rely so much on our perfect Mass attendance and other religious observances that, like the Pharisees, we miss the reason that we have religion and spirituality in the first place - to help us to know, love and serve Jesus the Lord.
Jesus takes this idea to a deeper level in the gospel reading. In the parable, it is the son who actually does his father's will that is pleasing to him, not the one who pays him lip service saying "yes" but ignoring his father's wishes. The son who appears to be rebelling against his father has a change of heart and obeys. The son who appears to be obedient at first, later rebels. Jesus uses this parable both to criticize the Pharisees and to encourage those sinners in the crowd who were mesmerized by his words and wanted to follow him.
We hear Jesus criticize the Pharisees often in the gospel. They were not bad men. In fact, Jesus could find no fault with their observance of the law and their moral lives. They lived the law perfectly. The criticism Jesus had of them was that they simply failed to believe in him. They said "yes" to all the commandments of the law, to all the ordinances of Scripture, but they said "no" to Jesus who came to bring the law and prophets to fulfillment. Because they trusted in their own goodness and perfect religious observance, they missed the opportunity of salvation which God was offering them in the person of Jesus.
On the other hand, it was the tax collectors, prostitutes and other sinners who came to Jesus in droves, drawn by his powerful words and the authority with which he cast out demons and healed the sick. Despite their past lives of debauchery, they were able to recognize God visiting his people in the person of Jesus. They were able to recognize the gift of salvation which came to them. They found the grace to change their lives and to believe in the good news of salvation.
When it comes down to it, Christianity is not only about following rules and observing commandments. Rather, it is a living relationship with the Lord Jesus. Like a marriage, we can't boil it all down to rules that we must follow. Like parenting, there is never a time when it is over, when we punch the clock and go home for the day. Faith is a commitment of love between people, a commitment of love between ourselves and Jesus. When we are in love, we never just try to do what is expected of us. Rather, we are always going out of our way for the other person. We never just want to spend a few minutes with our loved one, but a whole day and even a whole lifetime. We never want to give our loved one just a candy bar for Valentine's Day, but a whole box of chocolates! Love always goes beyond what is necessary, beyond what is expected, to serve the other person.
That is the way Jesus loves us. As Saint Paul tells us in the second reading, Jesus did not cling to his likeness to God but rather emptied himself to become one of us so that he could save us. Jesus went above and beyond the call of duty and the call of justice. Jesus responded to us out of his abundant love. And so, Jesus deserves our love in return. Jesus deserves us to say both "yes" to him with our lips and "yes" to him with the gift of our very lives.