How does Chapter 10 explain the role and power of a Sadguru in a devotee's life?

According to Chapter 10 of the Shri Sai Satcharitra, the Sadguru is portrayed as the one eternal God, distinct from other illusory gods. The text emphasizes that placing faith in the Guru's feet can lead to a change in one's fate, a concept described as striking "a nail over the lines of destiny." Pure service to the Sadguru is said to completely destroy worldly existence (Samsara) and help devotees cross the three types of miseries. Just as one trusts a boatman to cross an ocean, the chapter suggests one must trust the Guru to cross the ocean of existence (Bhavasagar). By his mere sight, attachments are broken and karmas are destroyed, leading to liberation effortlessly.