Based on Chapter 21, what is the underlying relationship between different Saints, even if they appear in different times and places?

Chapter 21 explains a profound and secret unity among all Saints. It teaches that while Saints may take incarnations in different locations and eras for specific purposes, they are "essentially inseparable from one another." The chapter clarifies that external factors like country and time may differ, but the spiritual signs and essence of one Saint are completely known by another. The central teaching on this topic, as stated in Chapter 21, is that "Inwardly, they are all one." This reveals a hidden, interconnected spiritual arrangement that transcends the physical world and its apparent differences.