From "Lectures on the Doctrine of Tenrikyo" by Shozen Nakayama the 2nd Shinbashira of Tenrikyo
...[In] more detail. As I said a while ago, Oyasama adopted the way she taught in the Ofudesaki to the situation at hand, thus conveying the teachings in various ways. The purpose of part 1, therefore, is to present a more orderly and systematic description of the teachings on the basis of the Ofudesaki. In other words, the five chapters of part I aim at extracting the contents of God's teachings conveyed by Oyasama mainly from the Ofudesaki and presenting them as an orderly whole. On the other hand, part 2, also in five chapters, describes how those who receive the teachings are guided and how they can attain the reconstruction of their minds; that is, it outlines the process whereby the awakening of the mind is accomplished. The five chapters of part I primarily presents God the parent's teachings, whereas the five chapters of part 2 primarily describe the way the mind become awakened, guided by these teachings."
Perhaps read the above more than once. It makes clear the importance of studying the Ofudesaki for anyone who would want to awaken and reconstruct their mind through understanding the teachings of our original parent and the "model of parental love" that fills its pages.