Why was the Nath Bhagawat (Uddhava Gita) considered such an important book in Shirdi?

Chapter 18 describes the Nath Bhagawat, or Uddhava Gita, as a "very divinely inspired book" that Sai Baba had read daily for the salvation of souls. Its importance stemmed from the belief that those who read it with faith could attain God instantly. The text highlights its profound spiritual value by stating that the dialogue within it between Krishna and Uddhava is even better than the famous dialogue between Krishna and Arjuna in the Bharata. It was considered to contain the "loving speech of Nath" and served as a key vehicle for Baba to bestow grace and instruction upon his devotees.