The character of Dory, in this scene from Finding Dory, is a lot like how Israel interacted with God through the Old Testament: https://youtu.be/i3kIpCzLzEo. They constantly forgot what God had done for them and continued to doubt and question him.
How often do we forget the work of God in our lives? Trust in God, when it boils down to it, is remembering His provision in the past. During the end of the message, consider offering congregants an opportunity to reflect on God’s grace and mercy.