In the Mikagura-uta and the Ofudesaki, God uses analogies to make the teachings easier to understand. Most of the early followers were farmers working in the fields. God uses terms like weeding, water, fertilizer, and harvest in explaining the teachings. Yes some may argue that by following the teachings, their harvest of crops were increased; but I believe that God is talking about how to save the world. I have constructed a diagram summarizing both the Ofudesaki and the mikagura-uta. Tomorrow, if you bear with me, I will use this diagram to explain another topic. 
Heaven's Truths, in Healing the Body 