According to Chapter 21, what is the underlying nature and unity of Saints?

Chapter 21 presents a profound concept regarding the nature of Saints. It states that Saints take incarnations from time to time in places they like for specific purposes, which may lead to apparent differences in country, time, and form. However, the chapter stresses that they are "essentially inseparable from one another." The text explains that the signs of one Saint are completely known by another, indicating a hidden network and understanding among them. The core teaching is that despite external variations, "Inwardly, they are all one." This suggests a single, universal spiritual consciousness manifesting through different holy personalities for the benefit of humanity, as detailed in the latter part of Chapter 21.