What does Chapter 10 say about the role and power of a Sadguru in a devotee's life?

Chapter 10 elaborates profoundly on the significance of a Sadguru, stating that the Guru is the 'one eternal God,' while other gods are illusory. By placing faith in a Sadguru, a devotee can have their fate changed, as the Guru 'strikes a nail over the lines of destiny.' The chapter further explains that pure service to the Sadguru completely destroys the worldly existence (Samsara), making intellectual struggles unnecessary. The Sadguru acts as a boatman, helping devotees cross the ocean of existence and overcome the three types of miseries. His mere sight can break the knots of the heart and destroy karmas, granting liberation effortlessly.