Can you clarify the difference between worldly service and spiritual Guru service as described in the text?

Yes, Chapter 0 draws a clear distinction between these two types of service. Worldly service, such as documenting the lives of notable public figures, is described as being limited by space and time and rooted in self-interest, so it does not produce eternal spiritual fruits. In contrast, spiritual Guru service, such as writing the biographies of saints, does yield spiritual benefits. The preface in Chapter 0 further explains that service can be performed with desire (Kamya) for worldly gains or selflessly (Nishkam) for liberation. Nishkam service is always considered superior and is the path toward the ultimate spiritual goal.