Based on the criteria in Chapter 48, how is the authority of a Sadguru established, and what is the core deficiency of those who don't meet this standard?

According to Chapter 48 of the Sai Satcharitra, the authority of a Sadguru is established through their ability to provide direct, full, personal experience to a disciple. The core deficiency of those who fail to meet this standard is a "total lack of self-experience," which renders their extensive verbal knowledge "verbally hollow." The chapter posits that while their explanations might be sweet, only an experienced person can manifest the pure "taste of experience." It rhetorically asks, "One who does not have experience himself, what will he give to the disciple?" This underscores that a Sadguru's authority comes from realized truth, not just recited scriptures or impressive talks.