Covetousness is the seed of greed and the dew of discontent. When we are trying to be satisfied with stuff, we are going against the will of God. The man recognizes Jesus’ authority, but He rebukes him because his request actually reveals the man’s covetous heart.
Covetousness comes in many forms but basically it is craving something that is not rightfully yours, or wanting something you don’t really need so much that it turns your heart to it rather than God. The Bible does not condemn riches, but it does sharply rebuke trusting in them and the pursuit of materialism. Covetousness is idolatry (Colossians 3:5 / Ephesians 5:5). We put something ahead of God and we act out of that impulse towards impurity. Whatever you consume has a way of consuming you. Covetousness will eat you up inside: you feed, and feed, and feed it, but it is never satisfied (James 4:1-3).
It is generally impossible for you to become satisfied until you learn to become content. To covet or to be greedy means that you are not satisfied with what God has provided for you and you constantly want more, even at someone else’s expense. It was the sin of Satan (Isaiah 14:12-14). It was the sin of Adam and Eve (Genesis 3:6). It was the sin of David (2 Samuel 12:1-8). It was the sin of the Pharisees (Luke 16:10-14). Covetousness is not about money only (1 John 2:16). We want what God has or think we deserve what God gives to others. Paul says it was “Thou shall not covet” which made him aware of his own sinfulness (Romans 7:7-8). Surely what was true of Paul is true of us all.
We want to feel secure, so we try and find it in stuff. We fail to notice the bigger issue of being held accountable before God. If you seek to know and to please God in all things, whatever the outcome, it will be the best outcome possible (Psalm 37:4 / Matthew 6:33 / Romans 8:28). If you seek yourself and your own goals, whatever the outcome, it will be pointless and empty, fading, and pregnant with spiritual poverty.