What does this part of the Satcharitra say about the concept of 'one-pointed devotion' and the role of a Sadguru?

Chapter 25 explains that Sai Baba, as the supreme embodiment of mercy, desires 'one-pointed devotion' from his followers. The text defines this concept by quoting Krishna's words to Uddhava: "The Sadguru is indeed My own form." Therefore, one-pointed devotion is described as the act of worshipping the Sadguru with love. It is asserted that a devotee who is faithful and filled with such devotion will not lack anything in attaining their desires. The Sadguru, in turn, wards off all misfortunes and removes the suffering of such a devotee. The story of Damu Anna is then introduced as a perfect illustration of this principle in action.