The last of God's Ten Commandments (Exodus 20:17) warns us that we should not covet our neighbors' possessions.
But what does "covet" mean?
The Catechism of the Catholic Church, which helps us to understand the Bible, says to covet is to want things in an unhealthy, unreasonable and sinful way.
Both the Bible and the catechism warn against being greedy. We are not supposed to love things more than we love God.
Each book also says we should not be envious of our neighbors. We are not supposed to be sad and jealous when our neighbors have more things than we do. Those bad feelings could lead us to sin against our neighbors by trying to take their things in unjust ways, like stealing or murdering. Instead, we are supposed to be happy that our neighbors have had good fortune.
There also are certain things belonging to our neighbors that we are forbidden to want, or that we should not want because our neighbors refuse to part with them. According to Exodus 20:17, these things include our neighbors' spouses, fields, houses, servants and farm animals.
In Matthew 22:34-40, Jesus said the greatest commandments are to love God and love our neighbors as ourselves. Doing this will help us to not covet our neighbors.