Delight yourself in the LORD,
and he will give you the desires of your heart.
-- Ps 37:4
Psalm 37:4 is a widely beloved verse in the Bible, with good reason. Its right up there with your Jeremiah 29:11's and Romans 8:31's and the like when it comes to getting that quick confidence boosts in God's eternal providence.
Yet... I submit that it may be one of those verses that might tend to fall into that Prayer-of-Jabez, name-it-claim-it syndrome. You know the idea: be good and do what God says and he'll give you what you ask for. Which, of course, flies quite in the face of the gospel reality that the Christian life will (and indeed should) involve at least some certain amount of suffering and trial (thus making us more Christ-like). And in some places, this sadly mis-focused mind-set that God is primarily here to give us the things we ask for has began to take quite an evident toll on the expanse of the kingdom.
"But what's wrong with God giving me what my heart desires?"
Well...nothing. As long as your heart desires the right things. And who can claim that their heart is constantly set on such things?
I don't believe that Ps. 37:4 is one of the most mis-interpreted verses in the Bible, rather I would offer that I believe it to be one of the most under-interpreted. That is to say, it holds so much more than is seen at first glance.
This verse is usually read in the sense that God "will give you that which your heart desires." But that's not what it says, in fact it is specifically worded to say that God "will give you the desires of your heart." Did you catch that? Not necessarily the things you desire, but perhaps He'll simply be giving you the very desires themselves, in the first place.
And that's when you move one step closer toward your heart being constantly set on the right things.
Yes, God can, and sometimes may give you the things that you do desire. This is a good thing - Christians should rejoice in the blessings of God that He gives us in this present world. There is nothing wrong with praying to be blessed - as long as its done with wisdom and a right understanding of what contrite prayer should truly be.
But a heart that is most completely delighting itself in the Lord is one that is not concerned with the affairs of this world, "where moth and rust destroy, and thieves break in and steal." Rather, a total delight in the Lord is a desire to have more of Him. And that is the desire that we know He loves to fulfill.