What is the primary purpose and main theme of the opening chapter of Shri Sai Satcharitra?

The primary purpose of Chapter 1, titled Mangalacharan (Invocations), is to set an auspicious beginning for the sacred work of writing the Shri Sai Satcharitra. As detailed within the chapter, this is achieved through a series of traditional invocations to deities like Lord Ganesha and Goddess Saraswati. The stated reason for this practice is the removal of all obstacles for the successful completion of the book. The main theme introduced is the non-dual nature of Sai Baba, as the chapter repeatedly identifies Him with the deities being worshipped, proclaiming that Sai himself is Ganesha, Saraswati, and the forms of Brahma, Vishnu, and Shiva.