From a sermon titled, “Battling the Unbelief of Envy” by John Piper:
Now the other reason this Psalm  is so great is because it gives so many reasons why we shouldn’t be unbelieving. It tells us why we should be totally restful and confident that God is for us. It tells us that he’s working in a way that, even if it looks like something’s going better for them, things are going to go great for us. Now let’s look at those. I wrote down six reasons that I see in this chapter for not being a in the grip of the unbelief of envy.
1) Verse 2: “They will soon fade like the grass and wither like the green herb.” So if you are starting to get envious about a wrongdoer, like the scoundrel who just won a million dollars, God says, “Wait a minute. You don’t want to be in his shoes. He is going to fade like the grass, and those who do the will of God abide forever” (1 John 2:15). So that’s argument number one.
It’s repeated in verse 9: “For the wicked shall be cut off but those who wait for the Lord shall possess the land.” And in verse 10: “A little while and the wicked will be no more.” So the first reason you shouldn’t let envy get the upper hand when you’re feeling it towards an unbeliever or somebody who is unrighteous is the thought, “Wait a minute. God has said in his word that this person is going to fade like a flower—very quickly. They’ll be gone and then whose will their prosperity be?”
2) Verse 3: “So you shall dwell in the land and enjoy security,” or, “and feed (pasture) on faithfulness.” In other words, that’s the reward that comes from trusting God. Trust the Lord and do good and you will pasture in a land that is green. Your desires will be met, which leads to the next one.
3) Verse 4: “Delight yourself in the Lord” (that is, “trust in the Lord,”), “and he will give you the desires of your heart.” Now that’s an amazing promise, because envy usually arises from not having the desire of your heart. You will see somebody that has something that you wish you had, and you’ll see that this desire is missing in this life. So the best way to fight is to go to this promise and say, “Now Lord, you have made a covenant with me in verse 4. You say that, if I will put my delight in you, you will give me the desires of my heart. So I am now going to delight in you.”
Now that’s a key step: trusting in God sufficiently so that you come to rest in who he is for you. It may also have a profound effect on the kind of desires you must have met in order to be content. But all the desires that you have will eventually be satisfied. That’s the essence of those amazing promises in Romans 8:32 (“If he did not spare his own son but gave him up for us all, will he not with him freely give you all things?”) or in 1 Corinthians 3:21-23 (“All things are yours, whether Paul or Apollos or Cephas or life or death or things present or things to come—all are yours, and you are Christ’s, and Christ is God’s”). The Bible makes staggering promises for people whose delight is in God rather than things.
4) Verses 5 and 6. “Commit your way to the Lord; trust in him, and he will act. He will bring forth your vindication as the light and your right as the noon day.” I can remember several years ago when Steve and Susan Roy were living across the street from us on Elliott Avenue over there. Steve had just resigned from InterVarsity. He did not have a position. We didn’t know whether he would be hired at Bethlehem, and he was painting on the weekends. And for Steve Roy, a theologian through and through, painting wasn’t what he wanted to do.
One day as we were walking across the street he said, “We really need some encouragement.” I can remember standing right there on the sidewalk. I said, “Here’s the promise for you today: Isaiah 64:4: ‘Who has seen a God like you, who works for those who wait for him?'” And they told me many times in succeeding years that they could remember that encounter on that afternoon as well. “God works for those who wait for him.” That’s the word. And that word “work” (in the Hebrew) is there in verse 5: “He will work for you. He will vindicate you.” And that word “vindication” is precious too, because one of the things that lies behind envy oftentimes is the feeling that things aren’t going as well as they ought to go. We’re getting a raw deal while, for somebody else who doesn’t even deserve it, things are going much better. What we want is vindication, and that’s exactly what is promised here. The vindication will come.
5) Verses 9 and 11: “For the wicked shall be cut off, but those who wait for the Lord shall possess the land,” and, “the meek shall possess the land.” Now if you say, “Well wait a minute. I’m not a Jew, and I don’t expect to inherit Palestine,” be careful. All of the promises of the Old Testament made to Jews will either be fulfilled to you the way they are fulfilled to Jews or better.
Where in the New Testament is there a better promise with almost the exact same words of verse 11? The Beatitudes, namely, “Blessed are the meek for they shall inherit the earth.” Alright, so I don’t get Palestine, just the earth. In fact, in Romans 4:13 it is those who are believers like Abraham who are called heirs of the world. 1 Corinthians 6 says that you will judge angels. To the disciples he said that they would sit on thrones judging the twelve tribes of Israel. We, the non-disciples or non-apostles, will judge angels. The Bible is so full of the most stupendous promises that it can remove the resentful feeling that simmers beneath envy.
6) Verse 11: “The meek will possess the land and delight themselves in abundant shalom.” This word is translated “prosperity” here, which probably has a ring that is not so helpful in our day. In the Hebrew it refers to the whole well-being that comes to those who trust.
So here’s a little example of how you fight the fight of faith in the morning, if envy starts to rise up in your heart. You get a text like this where it says, “don’t be envious,” and then you say, “Lord, if I’m going to get over this envy I’m going to need some powerful arguments for why I should be resting in you. Would you give me some?” And then you just read step by step. And as you get to one you stop, and you pray, “Lord open my eyes to see the wonder of this promise. And grant me by your Spirit the capacity to savor it, rest in it, believe it, walk by it, live in it and act on it today, please.” And you go to the next verse and work on it again until you find God meeting you and just lifting this ugly thing of envy off of you.