When you trust in the Lord, amazing things happen. Trusting in the Lord is placing your complete confidence in the Lord. It is more than intellectual assent, it is a total abandonment to God's will and work in your life.
The prophet compares those who trust in the Lord with a tree planted by a stream of water.
When fear and worry are running rampant, you can be a refreshing oasis to those around you. As you trust in the Lord, you will be a shining example of God's power and goodness to the world.