How does Chapter 21 explain the concept that all Saints are fundamentally one and the same?

Chapter 21 presents a profound teaching about the interconnectedness of Saints. It explains that although Saints may take incarnations in different times and places for specific purposes, they are "essentially inseparable from one another." The text clarifies that while external factors like country and time may vary, the inner signs of one Saint are completely known by another. This is because, as Chapter 21 states, "Inwardly, they are all one." This principle points to a unified, singular spiritual essence that all true Saints embody, suggesting their individual appearances are just different manifestations of the same divine reality, part of the "secret arrangements" of their ancient institutions.