What is the meaning of this story?

There is a young boy named Yosoji who is in his middle teenage years. His mother is very ill with the disease and his father is dead, so he is the head of the household. He decides to go to a fortune teller named Kamo Yamakiko and he is told there is a way to cure his mother of the sickness. He is to go to a brook that flows through Mount Fuji and worship the shrine called Oki-naga-suki-neo and to bring water back to his mother for her to drink. He is warned that it was a very dangerous journey but he seems to disregard that. The next morning Yosoji sets off for the brook but comes to a crossroad with three different paths to take. He is confused but a girl in a white robe comes to him and offers to lead him through the woods to the stream. She tells him to drink from the brook to prevent from getting the plague and to fill his gourd for his mother. She leads him back to the place where she had met him and said that in three days, he would want more water for his mother and she would be there waiting to take him back to the stream. Yosoji gives his mother the water and she becomes noticeably better. Three days had passed and the girl knew that Yosoji’s mother had been cured. Over a few weeks time, she leads him back and forth to the stream to collect water to cure the other sick villagers. Everyone is thankful and Yosoji wants to go back to the shrine to pray. When he reaches the stream, he finds that it is dried up. But, he prays to the shrine that the girl will show up so he can thank her for curing the villagers and his mother. She appears and he thanks her once again. But the time has come that she has to say goodbye to Yosoji. She starts swinging a camellia branch over her head and a cloud comes down. She is the great Goddess of Fujiyama. Yosoji gets down on his knees and starts praying to her and she throws down the branch to him. He carries it home, plants it, and takes very good care of it. The tree grows quickly, a shrine is built, and people worship the tree.

What is the meaning of this story?
A gift from a god can in time become a thing that is worshiped instead of worshiping the god who gave it.