Philippians 4:6-7

Be anxious for nothing, 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 [comprehension, will guard your hearts and your minds in Christ Jesus.

Anxious: Experiencing worry, unease, or nervousness, typically about an imminent event or something with an uncertain outcome, wanting something very much, typically with a feeling of unease.

Although written to the Philippians church, the principles of Philippians 4:6 applies to all believers today. When we have problems and worries, we often forget to pray to God about them. God does not promise to change every situation to our liking but what He does promise is to give us peace to endure during any situation. In other words,  He may not change our circumstances at the moment but He will change our perception about our situation to prevent any inner turmoil.