How does the author differentiate the spiritual value of writing about worldly figures versus writing about saints or one's Sadguru?

The preface in Chapter 0 draws a sharp contrast between these activities. Writing biographies of worldly Gurus is classified as a worldly service. While it may have value in public education, its importance and fruits are temporary and limited by space and time, and it does not yield spiritual benefits. Writing biographies of many saints is considered a form of Guru service that does yield spiritual fruits, but it is described as partial. The highest and most complete service, which grants the ultimate spiritual goal of salvation, is to write the biography of one's own Sadguru and engage with it through dedicated study and devotion.