How can writing a biography be considered Guru service, and what makes one type of biography superior to another for spiritual growth?

Writing biographies can indeed be a form of Guru service, but its spiritual value varies. Chapter 0 explains that writing about worldly figures like politicians or jurists is a worldly service with temporary fruits limited by time and space. While it may offer public education, it is often rooted in self-interest and does not yield spiritual benefits. A higher form of service is writing the biographies of many saints, which does yield spiritual fruits. However, the text identifies the best and most certain service as writing the biography of one's own Sadguru, with their command or by inner inspiration. This act, combined with personal study and devotion, is considered the most effective for attaining the ultimate spiritual goal.