According to Chapter 10, what is the significance of the Guru, and how does devotion to a Sadguru benefit a devotee?

Chapter 10 elevates the Guru as the one eternal God, stating that all other gods are illusory. By placing faith in the Sadguru's feet, a devotee can have their destiny changed, as if a 'nail is struck over the lines of destiny.' The chapter explains that serving the Sadguru destroys the worldly existence (Samsara) and helps a devotee cross the three types of miseries. The Sadguru acts as a boatman to cross the ocean of existence, and upon seeing a devotee's faith, He can grant them knowledge and liberation effortlessly.