If you belong to Christ, then you are Abraham's seed, and heirs according to the promise (Gal 3:29).

We the heirs of God live according to the promise. The promise is that God will bless us by giving us everything we need, and bless this world through us as a blessing. It was God himself who promised Abraham to give him a child and make him into a great nation so that through him all peoples on earth would be blessed. God wills, and is determined to do what he wills. That is what God’s promise means. He does not need our help. He does it for us. That is called God’s grace. Heirs of God live by God’s grace—the system in which his kingdom exists and all his blessings flow.

Yet, the world into which sin came is running according to a system that is different from that of God’s grace. The people who live there are the children born by the flesh like Ishmael, not the children born by promise like Isaac. The members of this kingdom are all involved in running a race against each other. Everybody tries to win by wanting to be the first, not the last, and nobody questions the validity of this system—the system of works: the more you work, the more you get.

The parable of the denarius workers begins this way:

For the kingdom of heaven is like a landowner who went out early in the morning to hire men to work in his vineyard. He agreed to pay them a denarius for the day and sent them into his vineyard (Matt 20:1-2).

As in many of Jesus’ parables, there is nothing unusual about the story at the beginning: it is very normal—ssomething of an everyday affair.

About the third hour (9 AM) he went out and saw others standing in the marketplace doing nothing. He told them, “You also go and work in my vineyard, and I will pay you whatever is right.” So they went. He went out again about the sixth hour (12 PM) and the ninth hour (3 PM) and did the same thing. About the eleventh hour (5 PM) he went out and found still others standing around. He asked them, “Why have you been standing here all day long doing nothing?" “Because no one has hired us,” they answered. He said to them, “You also go and work in my vineyard (vv. 3-7).”

Still, there is not anything so unusual. Note, however, that the amount of pay the owner promises to give these workers hired in later time is not specified. This becomes an important issue later in the story. What is also significant is the fact that the owner cares about these people “doing nothing,” which is a little unusual for such a landowner who is usually only concerned about the work to be done in his vineyard. Who are the people “doing nothing,” and who is the landowner who finds them and hires them? Then, comes a big surprise:

When evening came, the owner of the vineyard said to his foreman, “Call the workers and pay them their wages, beginning with the last ones hired and going on to the first.” The workers who were hired about the eleventh hour (5 PM) came and each received a denarius. So when those came who were hired first, they expected to receive more. But each one of them also received a denarius (vv. 8-10).

What is the point of this surprise? Look at the conclusion:

So the last will be first, and the first will be last (v. 16).

Interestingly, this parable is preceded by the story of the rich young man (19:16-30), which ends with the similar conclusion:

But many who are first will be last, and many who are last will be first (19:30).