I'm hanging out in Psalm 37 these days, trying to commit as much of it to memory as I may. (Intense weeks of school are always convicting for me, because I realize how much time I have to devote to learning things and how little of it I devote to Scripture on an ordinary basis.) Anyway, I've lingered in this passage more than once in my life for various reasons, so sitting down and memorizing it is a bit like cheating - but of course, that doesn't make it any less worth it.
The charge to "fret not!" is, of course, very timely. There a lot of things I could be anxious about right now - a lot of things I am anxious about - a lot of proverbial irons in the fire that might blossom to something lovely or explode and sear my fingers off at any moment. There are probably a lot of stupid things I'm committing while trying to juggle these potentially-explosive schemes... stupid things and willful sins.
Fret not!
There are, of course, many things made sure by this passage: God's care and love of the righteous, the destruction of the wicked, the innately evil-tending nature of fretting... but the one that always grabs me by the ear and gives me a good shake is the fourth verse:
Delight yourself in the Lord, and he will give you the desires of your heart.
It strikes me, then, that this is very much a prosperity-gospel sort of Psalm, though not the contemporary version. The Psalmist isn't saying, "Hey, love God and you'll get all the grademarks and honor and stuff you could ever want!" Can that even be accurately termed 'prosperity'? If so, what a squalid and cramped understanding of what it is to prosper!
But this is the prosperity Gospel according to God's economy, which quite simply boils down to this: if God is the deepest desire of your heart (if you delight in Him), then of course you get the desires of your heart. He gives you himself - has given and does give, from glory to glory: the love of the Father, the fellowship of the Son, the ministry of the Holy Spirit... and so he brings forth your (Christ's) righteousness as the light, your justice as the noonday.
Fret not.