Why are worldly relationships considered inadequate for spiritual progress, and what is the Guru's role in achieving the spiritual goal?

Chapter 45 explains that worldly relationships, including those with a mother, father, son, or wife, are ultimately unreliable for achieving the spiritual goal because they are tied to worldly interests. A son may focus on wealth, and a wife on her marital status, but they are not companions in one's spiritual pursuit. The text suggests that upon final reflection, only one's own self remains. In this journey, the Guru's role is paramount. The Guru is identified as the true Brahman and a "solid mass of Brahman-consciousness." Therefore, the means to achieve the spiritual goal is to renounce the transient world and meditate solely on the Guru, establishing a constant feeling of devotion.