What does Luke 12:16 mean?
Speaking to a crowd of thousands, Jesus is teaching how we ought to respond to the coming kingdom of God. That starts with letting go of things the world values. As He teaches the disciples that they may have to give their lives for the kingdom, a man from the crowd interrupts. He asks Jesus to demand his brother divide the family inheritance with him. Jesus refuses; if it's that serious, they should see a judge. More importantly, they should be adult enough to work it out themselves (Luke 12:1–15, 57–59).Since the topic of worldly possessions has come up, Jesus takes advantage. He warns the crowd that obsession with possessions is covetousness (Exodus 20:17). Just as earthly life is no comparison to eternity in paradise, so worldly possessions are nothing compared to treasures in heaven. To illustrate the point, He tells the parable of the rich fool.
God blesses a farmer. His land has been fertile and is even more so this season. The context of the story suggests this is not because of anything specific he did. The harvest may have been a matter of good weather or because God chose to reward him for his obedience. Either way, Jesus does not look on either the wealth or the good harvest in a negative way. What's judged here is the man's attitude towards his money, which he values more than a relationship with his Creator.
The rich man decides to build bigger barns and retire to a life of leisure. He is focused on the comforts of his life on earth. He does not know that he will die this very night. All his wealth will go to another. Because he prioritized possessions and not God, he will have nothing to show in eternity (Luke 12:17–21).