I will sing of the Lord’s great love forever; with my mouth I will make your faithfulness known through all generations. — Psalm 89:1
In addition to being prayers and praise songs, some of the psalms also retell portions of Israel's history. The Israelites would sing them together to praise the past deeds of their Deliverer (e.g. Psalm 136). Today's worship songs don't list what He's done for us specifically like the Israelites' songs did, but we should definitely follow their example of remembrance.
Christians often use the word testimony to name the story of how they accepted Jesus as their Savior. Salvation is a great proof of God's love, but His work doesn't stop there. He daily fills our lives with His provision, nearness, and loving patience. When we recognize what He has done for us, we can be storytellers of His faithfulness, like the psalmist. We gather strength for the challenges ahead when we recall the victories He granted in the past, and our ongoing testimonies of His faithfulness display His love to those who don't know Him personally.
When you feel troubled, tell yourself your stories of His faithfulness. When did you feel His comfort when you called on Him for help? When has He provided for your needs beyond expectation? Just as He did then, your unchanging God will never stop caring for you.
Father, thank You that You've never stopped working in my life. When I am fearful, help me recall Your goodness and trust You more. Give me opportunity to tell others what You have done for me, so they will come to trust You, too! Amen.