It was noted that the Solar Ancestors in Ancient Egypt taught that we, as Spirits (Ka), should redeem the personality of our lower self (Ha) and, while embracing it, return to and reunite with our Soul (Ba). But what is the element that is missing in this equation? It is the metaphysical heart or Ab. Once we activate that, we may be restored as an Akh, and the resulting fifth element is our Solar Self, the Sahu (in 2012 I posted a short clip on You-Tube showing this:
https://www.youtube.com/watch?v=AuWIs1Xy6Hk ). The Buddhists of India used the terms: the Stream-enterer, the Once-returner, the Non-returner, and then by reaching the fourth stage called Arhat, they entered Nirvana as a Buddha.
I wrote about the sign of the square in a limited edition booklet entitled The Sign of the Quatrefoil (ISBN 0-975013904) ten years ago, and noted the human transition in ancient times from Trinity to Quaternity, tracing the meaning of the Hebrew Tetragrammaton and Greek Sacred Tetrakys. Think of the Creator as being represented by a triangle and the Created by a square. Contemplating sacred geometry can be an aid in igniting the metaphysical fire.
https://en.wikipedia.org/wiki/Ancient_Egyptian_concept_of_the_soul