The peace these verses describe is not the absence of trouble — John 14:27 was spoken the night before a crucifixion, and Philippians 4 was written from a cell. It is a guarded heart in the middle of unrest, which is why it is called a peace that surpasses understanding.
Several of these verses come with a practice attached: pray instead of worrying (Philippians 4:6), keep your mind fixed (Isaiah 26:3), take one day at a time (Matthew 6:34). Peace in Scripture is something you cooperate with, not something you wait to feel.
If anxiety is your reason for visiting, the anxious mood on the home page gathers this set and more, with prayers written for exactly that moment.