Earthly wealth that is temporary is ultimately worthless. What the farmer owned was valueless to him after his death. The selfishness of the farmer is a result of his wealth, which Jesus condemned. The sin of covetousness and the acquiring of assets is futile and self-defeating, it is dangerous to focus on wealth. Covetousness is a self-seeking desire which is usually over material possessions that someone else owns.
Covetousness grows to greed and an all-consuming lust.
A covetous person is an idolater. If a person gives in to the desire to covet, they usually are self-centred and continually yearn and end up a fair distance apart from God. The farmer is an example of those who are not rich with the things of God. True life is found in God, through His Son Jesus Christ. Jesus warned His disciples to seek after everlasting spiritual benefits.