How does Chapter 10 explain the power of a Sadguru to change a devotee's life?

Chapter 10 of the Shri Sai Satcharitra describes the Sadguru as the one eternal God who can fundamentally alter a person's life. It uses the powerful phrase that by placing faith in the Guru's feet, He "strikes a nail over the lines of destiny," which means He can change one's fate. The chapter further explains that the Sadguru acts as a boatman, helping devoted followers cross the three types of miseries and the entire ocean of worldly existence (Bhavasagar). Through pure service to the Sadguru, the difficult cycle of Samsara is completely destroyed, demonstrating the Guru's immense power over a devotee's spiritual and worldly path.