How will people know? Does it take a miracle to convince people? Are there higher beings talking but no one is listening?
So, words will not do. Or reading books. When the time is right, these souls will be revealed. Sorry Pr. but writing a book about anything does not give you any more clout than anyone else.
So, what souls require is the experience. To sit in front of one of these beings and find themselves taken into the awareness of their true spiritual form and personality. Body-less while in a body, and the warmth of love and lightness, Bliss even. These quality's are our birth rite, it is what we all are, naturally. I won't tire of saying this.
Older souls will have known better times in previous lives, so will be slightly discontented with their lot to some degree.