Isaiah 55:10-11 "Rain and snow come down from the sky. They do not go back again until they water the earth. They make it sprout and grow so that it produces seed for farmers and food for people to eat. (11) My word, which comes from my mouth, is like the rain and snow. It will not come back to me without results. It will accomplish whatever I want and achieve whatever I send it to do."
Water is evaporated from the sea (and land) and rises in the warm air. As the air rises it cools and evaporates moisture which condenses to form clouds. Eventually the droplets coalesce to form raindrops and fall as rain or snow. As the water falls as rain (or snow) it soaks into the ground and eventually finds it's way into creeks, streams and rivers. It flows to the sea where it is eventually evaporated by the heat of the sun. The evaporated water condenses into clouds and then falls as rain, to start the cycle over again. It is a reoccurring cycle which will happen no matter what.
God's promises are the same for you and I. What He has spoken over you will happen no matter what. His words are like rain which recycles in the earth. It will come back with results not empty handed. God is faithful to His promises if we just believe. It is a spiritual cycle of truth.
Maybe you are wondering about your calling or ministry. Maybe you think that God could never use you. Maybe you think that your destiny will never happen. I am here to tell you that God will fulfill His promise in you. Just wait on him. Just believe in His truth.