The trees will bloom and grow fruit when it rains. But when it doesn't rain, the trees cannot produce fruit. Sometimes there is a river that runs through the desert. The ground close to the river can grow many plants. Animals and men from all over the desert will come to the river to drink.
Life is abundant next to the river.
The trees will always be able to bloom and produce fruit. But don't go very far from the river or you will see the withered trees. God says that you are like the trees in a spiritual way. If you want to be a very strong and green tree with much fruit, you must trust Him and obey him. Blessed is the man that trusteth in the Lord, and whose hope the Lord is.