What is the role and significance of a Sadguru as described in the opening of Chapter 6 of Sai Satcharitra?

According to the beginning of Chapter 6 of the Sai Satcharitra, the Sadguru's role is paramount in both spiritual and worldly matters. The text likens the Sadguru to a helmsman who ensures that the boat of one's life safely reaches the far shore. It emphasizes that the very utterance of the word 'Sadguru' brings Sai Baba to mind, creating a tangible sense of His presence and blessing hand on the devotee's head. This chapter highlights that the Guru's touch is wondrous, capable of burning away the ego, which is described as a subtle body that even the fire of dissolution cannot burn.