In the author's opinion, who is performing the most certain and best form of written service for salvation?

According to the author's humble understanding expressed in Chapter 0, the person performing the best and most certain written service for salvation is the devotee who writes the biography of their own Sadguru. This service is ideally undertaken by the Guru's command or through inner inspiration. The author emphasizes that it must be done with a firm resolve, pure heart, excellent faith, selfless love, and unwavering devotion. This service, which also involves studying the work and encouraging others to do the same, is considered the highest form of written devotion.