In one penetrating parable, Jesus leaves us with a lot to think about. We know that we can't work our way into heaven. We can never do enough good in this life to earn everlasting retirement, whether we start our Christian service at six in the morning or at five in the evening. WE can never do enough to fully fund a future in God's eternal kingdom.
We also learn that we're all in need of God's grace and forgiveness, every single one of us. In the kingdom economy, we can be grateful that God chooses to be generous.
We learn, too, that in God's service, we do not all have the same work to do. Some of us can teach, others sing, others cook, others organize, others visit the sick, others evangelize, others serve the poor, others care for children, others repair the church roof. Like the workers in the vineyard, we have different tasks to perform, with different time frames, energy levels and abilities.