According to the preface, what makes a spiritual text like the Shri Sai Satcharita effective in inspiring faith and devotion?

The preface to the Shri Sai Satcharita, as explained in Chapter 0, distinguishes between different types of poetic books. It argues that a book written solely on scholarship and intelligence will not last or inspire genuine faith. For a spiritual book to leave a lasting impression on seekers, it must possess qualities of inspiration, grace, and divine gift, which are bestowed through a Guru's grace. The Shri Sai Satcharita is described as a 'grace-filled (Prasad-janya) book,' and it is this quality that ensures it will be cherished by any seeker-devotee and inspire them to study it daily, fostering their trust and devotion.