Akhetnu
The supreme god Amun of the ancient Egyptian new kingdom solar theology (originally one of the primordial chaos-gods of Hermopolis) emerged as the being who acquired the attributes of all the gods, to the point where all the gods were theophanies of Amun:
The Ennead combined is Your body.
Every god joined in Your body, is Your image.
You emerged first, You inaugurated from the start.
Amun, whose name is hidden from the gods.
Oldest elder, more distinguished than these,
Tatenen, who formed [Himself] by Himself as Ptah.
The toes of His body are the Eight (Ogdoad).
He appeared as Re, from Nun, so that He might rejuvenate.
He sneezed, as Atum, from His mouth and gave birth to
Shu and Tefnut, combined in manifestation.
-Hymns to Amun, Leiden Papyrus I (c. 1250 BC), Chapter XC
As we can see, the composer of the hymn envisions Amun as incorporating the theologies of Hermopolis (the Ogdoad), Heliopolis (the Ennead), and Memphis (Ptah) into one single, primal entity. In addition, Amun acquires both the dynamic creativity of Ra and the very substance of Nun from which the former emerged. His creative primacy is further emphasized later in the text:
The One who initiated existence on the first occasion,
Amun, who developed in the beginning,
whose origin is unknown.
No god came into being prior to Him.
No other god was with Him who could say what He looked like.
He had no mother who created His name.
He had no father to beget Him or to say : “This belongs to me.”
Who formed His own egg.
Power of secret birth, who created His (own) beauty.
Most Divine God, who came into being Alone.
Every god came into being since He began Himself.
We are now presented with Amun as a sort of primal ‘substance’ from which all else originated. But beyond that, Amun is said to be beyond knowledge (not even the gods are said to know his true nature), and pre-existed the universe that he created:
One is Amun, who keeps Himself concealed from them,
who hides Himself from the gods, no one knowing His nature.
He is more remote than the sky,
He is deeper than the netherworld.
None of the gods knows His true form.
His image is not unfolded in the papyrus rolls.
Nothing certain is testified about Him.
He is too secretive
for His Majesty to be revealed,
He is too great to be enquired after,
too powerful to be known.
While the ancient Egyptians remained polytheist in that they had a multiplicity of divine forms and their physical manifestations, there was at the same time a fundamental unity underlying them and the world in the form of Amun, that was beyond any mortal (and even immortal) comprehension. Being more remote than the sky, and deeper than the netherworld, he can also be seen to encompasses the universe and all within it.
Centuries later, the 18th century German philosopher Emmanuel Kant wrote about the two aspects of the universe: the noumenal and phenomenal. The phenomenal is the world as we perceive it with our five senses, integrated with our minds; the noumenal, however, is the ‘thing in itself’ (ding an sich), which is the actual underlying reality that we are attempting to fathom. According to Kant, however, reason and the senses cannot approach the noumenal directly, since all the information they gather and present about it is filtered through themselves and hence is of the phenomenal. Kant placed ideas of the soul or the divine in the realm of the noumenal, and in the 1950s Alan Watts pointed to the phenomenal as the area of scientific inquiry and the noumenal as the subject of mystical and religious experience.
Far to the east, the Buddhist doctrine of Sunyata (the Void) holds that the ultimate identity of all people and things is the Void, or emptiness. This is not a nihilistic emptiness wherein nothing exists, but rather the realization that all things are ultimately interconnected and integrated as a single universe. Thus, the differences and demarcations we make between self and other, or objects from their surroundings, are illusions: ascribing a personal, transcendent identity to anything is empty. There may be multiple ways of people looking at the phenomena of reality (for the convenience of our perceptions), but there is only one reality in and of itself. (It should be noted that the brains of monks who meditate shut down the part of the brain that draws the difference between the person and their surroundings, further shedding light on this notion.) The Void is also empty in that it is beyond the ability of a person to think about or find without meditation or mystical experience.
Bringing all three philosophies together, we find that the ideas underpinning Amun, the noumena of Kant, and the Void of Buddhism can all be seen as pointing to the same place with different signs. They each envision an essential and single reality to the universe that is beyond the ability of humans to comprehend in a normal fashion, and beyond what most would consider the world that we can see, touch, smell, taste, hear, or think about. It is this shared transcendent experience of ‘cosmic reality’ that all religions attempt to approach in various ways.
This is not to ignore the differences in the experience of the Buddhist and the Egyptian: the Void of the former precludes the individual soul that the latter held so dear. However, I would at this point invoke the Egyptian ideas of Kheper and Ma’at. Kheper is the aspect of Amun that manifested the other gods, and was the principle of (as translated) “coming into being”. It is also the principle of eternal life illustrated by the scarab beetle rolling its ball of dung across the ground, like the sun disk of Ra that traveled across the sky to give life to all on Earth and rejuvenation to the Bas of the dead in the Duat, so that they may continue to live eternally. Meanwhile, the Void emphasizes the constant flux of the universe that is also “coming into being” with each and every new moment.
Ma’at is the fundamental order, laws and way of the universe; the offering prayer of Ma’at to the gods states that “…she is everywhere…your heart does live in Ma’at; all that you eat, all that you drink, all that you breathe is of Ma’at….” This universality and the other parallels with the Tao as the way of the universe are obvious, and like Amun the Tao is also ultimately considered unfathomable by mortal minds. As the Void is predicated on the flux and change of each new moment, and the Tao is the ebb and flow of the universe, so too can Ma’at be seen as the embodiment of the same causation and laws inherent in the world around us.
Now, while the Void (and perhaps the Tao) indeed preclude the idea of an immortal individual soul sustained by the process of Kheper, it also has an immortality of a different sort. Namely, that which comes from being one and the same with the ever-changing and ever-existent flow of reality also embodied in Kheper and Ma’at; one that is, like Amun, more than what we can sense, and is indeed the foundation and essence of existence itself.
Ancient Egypt envisioned one’s personal life force as an individual Ka that originated and was passed down through the Gods, to the Pharaoh, and via fathers to their sons. Within Zen Buddhism or Taoism, however, one can understand everyone’s Kas as actually one single flowing continuum that appears to be this transmission. So both Egypt and Zen transcend death by envisioning it as a continuation of life via the process of eternal coming-into-being: the former with one’s soul renewed by synchronizing it with the life-giving ‘Kheper’ power of Ra, and the latter by the self actually being the coming-into-being in the first place
neosalexandria 
this sounds a lot like hermeticism.