Can you explain the concept of 'service through books' as it relates to a Sadguru and their followers, and how this fosters a spiritual community?

According to the preface in Chapter 0, a Sadguru accepts two forms of 'service through books' from devotees. The first is when the Guru themselves authors a great work. The second, more relevant for community building, is when a Sadguru has their biography written by a devotee. This biography then becomes a medium for service for the entire congregation. By studying the text and performing 'Parayans' (devotional readings), the writer performs Guru service, and the readers also participate. This shared practice of studying the Guru's life creates a powerful communal experience, serving 'Jan-Janardan' (God in humanity) and helping all devotees achieve the purpose of their lives together.