"Do not be anxious about your life." (Matthew 6:25)
"Why do we worry? Because we don't believe. We're not really convinced the same Jesus who can keep a sparrow in the air knows where our lost luggage is, or how we'll pay that car repair bill. Or if we believe he can deliver us through our difficulties, we doubt if he will. We let Satan sow seeds of doubt in our minds about God's love and care for us.
The great antidote to anxiety is to come to God in prayer about everything. "Do not be anxious about anything, but in everything by prayer and supplication with thanksgiving let your requests be made known to God. And the peace of God, which surpasses all understanding, will guard your hearts and your minds in Christ Jesus" (Philippians 4:6-7). Nothing's too big for him to handle or too small to escape his attention. Paul said we're to come to God "with thanksgiving." We should thank him for his past faithfulness in delivering us from troubles. We should thank him for the fact that he's in control of every circumstance of our lives and that nothing can touch us that he doesn't allow. We should thank him that in his infinite wisdom he's able to work in this circumstance for our good. We can thank him that he won't allow us to be tempted beyond what we can bear (1 Corinthians 10:13).
The promised result is not deliverance, but the peace of God. One of the reasons we don't find this peace is that all too often we won't settle for anything other than deliverance from the trouble. But God, through Paul, promises us peace, a peace that is unexplainable. It will guard our hearts and minds against the anxiety to which you and I are so prone."
- Jerry Bridges, Holiness Day By Day