Well, I have often found that quoting Scripture is a great way to defeat the enemy when I start to worry or have fear.
In fact, it’s a great idea to write down a promise from God’s Word about fear (Philippians 4:6-7, Isaiah 41:13, 1 Peter 5:7) and carry it around in your pocket wherever you go. Eventually, you’ll have it memorized and can use it when you’re tempted to doubt or fear!