How does the text describe the role and supreme importance of a Guru in a disciple's life?

Chapter 18 presents the Guru as an all-encompassing figure of supreme importance. The Guru is described as God manifest, embodying Brahma, Vishnu, and Maheshwara, and is essentially the Supreme Lord. The text emphasizes that the Guru is a mother, a father, and a protector even when God is angry. However, it warns that if the Guru becomes angry, there is no other protector. As detailed in Chapter 18, the Guru's word is a guiding ray of light on a difficult path, and they serve as a director for worldly activities, a guide for spiritual practices, and a teacher of righteousness and detachment.