The following is from William MacDonald’s Believer’s Bible Commentary:
“Worry is unnecessary; there is no need for us to bear the burdens when He is willing and able to bear them for us. Worry is futile; it hasn’t solved a problem yet. Worry is sin. A preacher once said: ‘Worry is sin because it denies the wisdom of God; it says that He doesn’t know what He’s doing. It denies the love of God; it says He does not care. And it denies the power of God; it says that He isn’t able to deliver me from whatever is causing me to worry.’” “Be careful for nothing; but in every thing by prayer and supplication with thanksgiving let your requests be made known unto God” (Philippines 4:6). “Casting all your care upon him; for he careth for you” (1 Peter 5:7).