According to Chapter 21, what is the underlying unity among all Saints, and how does this concept relate to their incarnations?

Chapter 21 delves into a deep spiritual principle regarding the nature of Saints. It posits that all Saints are "essentially inseparable from one another." Although they may take incarnations in different places and at different times for specific purposes, their core essence is one. The text explains that while "Country, time, and objects may differ," the signs of one Saint are completely known by another. This suggests a secret, interconnected network and arrangement among them. As Chapter 21 states, "Inwardly, they are all one." This teaching highlights that the external differences in their forms or methods are superficial, and they are all manifestations of the same singular, divine consciousness.