We just wrapped up a sermon series on the ten commandments in Deuteronomy 5. The last commandment is unique: "You shall not covet." The first nine commandments start with outside actions - not making idols, sabbath keeping, not murdering. The last commandment starts with the inside: the heart, and our selfish desires.
When we talk about coveting we're talking about the things we want. And scripture points us to the one thing we need, and therefore the one thing we ought to desire above all else. As Phil Ryken says in his book on the Ten Commandments: "The first thing, the main thing, the only thing that really matters is to trust in Jesus. He is enough for us. Really he is."
Jesus said: "Seek first the kingdom of God and his righteousness, and all these things will be added to you" (Matt. 6:33). Get Jesus. And you get everything you really need.
Below is a parable about what happens when you obtain the one thing that really matters.