How can devotees engage in community-building and serve their Guru through literary works, as described in the preface?

According to Chapter 0, a Sadguru accepts service from devotees through books in two ways. Devotees can participate in the second form of this service, which involves the study of biographies written by other devotees. By performing Parayan or Saptah (dedicated reading over a period) of a detailed Guru biography, an individual performs Guru service. When this is done in a group, it builds a community. The text notes that the writer gains merit for serving God in humanity (Jan-Janardan) and public service, while the other devotees in the congregation also achieve their life's purpose, thus fostering a strong spiritual community.