Why can't I find details about Saint Augustine in this book? Isn't it important to study the lives of all saints?

The texts we are examining do not contain information about Saint Augustine. Instead, they focus on a different kind of lesson. According to Chapter 19, the essence of the teaching is that "As the action, so the hearing; as the practice, so the benefit." This puts the responsibility for spiritual growth on the seeker's own actions and devotion. The book highlights Sai's teaching that true success is attaining spiritual wealth, as no one is immortal. Rather than collecting information about many different saints, the guidance in Chapter 19 suggests that a devotee should surrender with an undivided heart to their chosen path and Guru to experience happiness and contentment through the ties of their unique spiritual connection (Rinanubandha).