The thing that people find hardest to believe about the gospel of Jesus Christ  is not that it involves a man rising from the dead; it is not that it involves believing in a personal deity who made the world with a word; it is not even that a good God could allow a world where there is suffering. Far more difficult to believe is that God’s grace, which means forgiveness of sins, is really free.

We have such a deeply ingrained expectation that it isn’t like that, that we have trouble hearing it and understanding it. We are so used to living in the world of ungrace that we cannot bring ourselves to really understand what the world of grace might actually look like.

There is no such thing as a free lunch.

Money doesn’t grow on trees.

The world doesn’t owe you a living.

There is no gain without pain.

These are the principles of the world of ungrace. It’s a world where you get what you deserve. It’s a world in which you look with pride on your achievements and hide with shame all your failures. It’s a world in which you are constantly judged, marked, critiqued and evaluated. It’s a world in which you take any advantage you can because only the fittest, or smartest, or prettiest, survive.

Karma, where (to quote Savage Garden) “what you get is what you give returned”, seems so much more logical and just.

Even though I know about grace, and I have experienced grace, the old mental habit of ungrace is stubbornly persistent. I work to bolster my list of achievements because it makes me feel like someone of whom I can be proud. I judge others for their failures, and carry my grievances with me like a handbag. I am forever comparing myself to others. I am an oldest son, after all.

When it comes to our standing before God, we fall into one of two errors of ungrace. We either presume on God’s favour, subconsciously believing that God’s free gift to us in Christ comes to us actually because we are really rather loveable and deserving; or we think that we could never be acceptable to God because we are really rather unacceptable to everyone else. Strangely, sometimes the same person can hold to these two thoughts at the same time.

This idea of God’s grace is the beating heart of Jesus’s teaching. Now, he never mentions the word ‘grace’. But he teaches about it constantly. There’s the parable of the lost son welcomed home by the father, despite everything. There’s the one about the banquet which is thrown open to those who by rights have no expectation of an invitation. But the parable which causes us the greatest degree of bewilderment is the parable of the workers in the vineyard from Matthew 20.

The outline of the story is simple. The owner of the vineyard has some work he needs doing. So, first thing in the morning, he finds some workers and agrees to pay them a full day’s wage. But the work isn’t getting done, and he decides that he will hire some other fellows to help out. So he goes back to the marketplace where the as-yet unhired workers are standing around, and he calls them in, telling them somewhat vaguely he will pay them “whatever is right”. He does this at 9 am, at noon, at 3 pm; and then, with the shadows of the day lengthening, at 5 pm. That’s five different groups of workers, some of whom have worked a gruelling 12 hour day by the time it is all finished. Then, when it comes time to settle up the payroll, the landowner hands out exactly the same pay to each worker.

It’s a disastrous piece of workplace relations, isn’t it? You can easily imagine how the first group of workers felt when they saw what was going on. It is massively, blatantly and completely unfair. They have worked the whole sweaty day. The last group only chipped in at the end for an hour. And yet, the same reward is given to all. No wonder someone speaks up and says “These last worked only one hour, and you have made them equal to us who have borne the burden of the day and the scorching heat”.

I hope you can see his point and feel something of his pain. We have an acute sense of fairness, don’t we? It is taught to us in pre-school and probably even before, and it lasts for our whole lives. We don’t like that there is an unfairness, especially when it is biased against us.

I saw an experiment recently on YouTube, where two caged Capuchin monkeys were rewarded for giving the scientist a stone. The first monkey was given a grape for each stone. The second monkey was given a piece of cucumber.

The monkey who was given the cucumber was happy at first with his reward. But when he saw that the other monkey was being given sweet luscious grapes, he started to become angry, and he threw the cucumber back at the scientist. Who wants a cucumber when a grape is on offer?

This video was used in a TED Talk as evidence of moral behaviour in animals. And it was, after a fashion. Though perhaps it better illustrated the reverse: that what we call ‘moral’ behaviour is really no such thing, but just what monkeys would do in the same situation.

Let’s be frank: Jesus’s vineyard owner has been quite unfair. And I’ll bet it made employing workers the next day a bit more difficult, too. But he defends himself by saying:

“Friend, I am doing you no wrong; did you not agree with me for the usual daily wage? Take what belongs to you and go; I choose to give to this last the same as I give to you. Am I not allowed to do what I choose with what belongs to me? Or are you envious because I am generous?”

He has a point: he has not been dishonest and he has not dishonoured any contracts or agreements. The workers knew what they were getting when they started, and worked happily for that. It was only when they saw what others were getting that it became an issue for them. What is the grounds for their complaint, really? No injustice has been done, no promise has been broken.

But it still feels uncomfortable, doesn’t it? Especially when Jesus says that this is what the kingdom of heaven is like—where the last will be first, and the first will be last. We don’t like things being so out of kilter, or so unexpected. We are used to the economy of exchange: where equal work gets equal pay; where debts accrue, and interest is earned, and taxes are inevitable; where everything has a price.

But here, in the kingdom of heaven, the human way of ordering things is overturned. We are dealing with an economy of grace. And what does that look like? How does that operate?

The kingdom of heaven contains people I wouldn’t choose, that’s for sure. It contains people who haven’t served all their lives as decent, honourable citizens. It contains people who have committed all manner of crimes. It admits people despite everything and not because of anything.

But it operates that way because of whose kingdom it is. It belongs to the Father of our Lord Jesus Christ, who, from the beginning, made the world not from necessity but out of the wealth of his freedom and out of the pure generosity of his character.

And his economy is the economy of the gift. Not, I hasten to add, the sort of manipulative gifts we give—the bottle of wine to the client, the gift given to one who loves us, or whose love we want to purchase. The giving of the divine gift springs entirely from his freedom to give. And the pattern of his giving is extraordinary: he gives not because he is impressed, but because he can. He gives to those who least deserve it because it shows to us that what comes from God is not a wage that we have earned but a gift out of the overflow of his heart. He doesn’t have to give: he wants to.

I recently went to jail to visit a friend of mine who is a prison chaplain. To be honest, I was going to see if the gospel of God’s grace was true. Could it really work for people in jail? Let’s not be romantic about it: people are in jail because they have done some pretty bad stuff. We don’t put people with traffic fines in prison. These are the rightly unacceptable people.

The answer came in the form of the violent offenders’ Bible study. There I heard from a young man who had been in prison long enough already that I knew he had done something truly hideous. Was it murder? Could have been. I was afraid to ask. And yet there he was: praying with me, reading the Bible with me, a brother in Christ.

It’s an outrage, really. That kind of person is not the sort of person who you’d want to have in your church. They don’t deserve to be there. But the God of Jesus Christ is the God of such outrages. And here’s the question that the parable is asking you: can you live with these divine outrages? Can you live with a God who doesn’t recognize the pecking order? Can you live with a God who reverses the normal order of things? Because I am sorry, but you don’t have an alternative.