Fret not thyself in any wise to do evil. Psalm 37:8.
Fretting means getting out at elbows mentally or spiritually. It is one thing to say ‘Fret not,’ but a very different thing to have such a disposition that you find yourself able not to fret. It sounds so easy to talk about “resting in the Lord” and “waiting patiently for Him” until the nest is upset—until we live, as so many are doing, in tumult and anguish, is it possible then to rest in the Lord? If this ‘don’t’ does not work there, it will work nowhere. This ‘don’t’ must work in days of perplexity as well as in days of peace, or it never will work. And if it will not work in your particular case, it will not work in anyone else’s case. Resting in the Lord does not depend on external circumstances at all, but on your relationship to God Himself.
Fussing always ends in sin. We imagine that a little anxiety and worry are an indication of how really wise we are; it is much more an indication of how really wicked we are. Fretting springs from a determination to get our own way. Our Lord never worried and He was never anxious, because He was not ‘out’ to realize His own ideas; He was ‘out’ to realize God’s ideas. Fretting is wicked if you are a child of God.
Have you been bolstering up that stupid soul of yours with the idea that your circumstances are too much for God? Put all ‘supposing’ on one side and dwell in the shadow of the Almighty. Deliberately tell God that you will not fret about that thing. All our fret and worry is caused by calculating without God.