Who or What is It?
The fact that the phoenix makes an offering to Helios suggests an occult origin to this legend, because occultists are sun worshipers—more accurately, they worship the spirit of illumination. The priests of Egypt were master occultists, and famous for their veneration of the sun. They associated the bennu bird with the daily death and resurrection of the sun.
Let's see what modern occultist Allan J. Stover said about this bird in the January 1948 edition of The Theosophical Forum:
The legend of the Phoenix Bird, periodically reborn from the ashes of its consumed body, is a myth from the mystery language of the Ancient Wisdom, so old that no man knows the time or place of its origin.... [It is] not an image of fancy and superstition, but a symbol of eternal truth.
There is hardly any consensus on what entity the phoenix is supposed to represent. The majority opinion seems to be that it stands for Lucifer, by which they mean Satan. (Technically speaking, Lucifer is the Seed of Satan, the King of Babel, but very few people understand that).
Some Christian teachers imagine that the phoenix stands for the Antichrist, or the Occult/Mystery Brotherhood, or individual initiates of the Mysteries, or the once-and-future kingdom of Babel itself. Others see the bird as the representation of a concept rather than an entity, arguing that it stands for immortality through rebirth and resurrection.
In my opinion, it's all of the things listed above.
As we study the traits of the mythical fire-bird and related concepts, you will see how they can be applied to many aspects of Satan's kingdom.
The Connection to Hidden Wisdom
The Phoenix is one sign of the secret orders of the ancient world and of the initiate of those orders, for it was common to refer to one who had been accepted into the temples as a man twice-born, or reborn. Wisdom confers a new life, and those who become wise are born again.
These initiates are on a centuries-long mission, which is why they refer to themselves as the Order of the Quest or Brotherhood of the Quest. This quest is both an individual undertaking and a collective one, and it is very grand. They seek the deification of mankind.
Again from Allan J. Stover's article in The Theosophical Forum we read:
There is a thread of esotericism running through all these legends [of the phoenix], linking the thought of east and west, vitalizing the myth, until the truth it embodies shines forth like a many faceted jewel, a constant reminder that there is no death, but only endless change and evolution, as mankind progresses from humanhood to godhood.
I could produce dozens of similar quotes from occultists like Allan Stover, all preaching the evolution of humanity to a godlike state through knowledge and self-will. They view death as a force of transition that is necessary for now but will eventually be overcome entirely through ingenuity.
To reiterate: In the philosophy of the Occult, the secret wisdom/knowledge (a.k.a. the Mysteries) leads to a spiritual rebirth, which leads to deification, which will lead to immortality.
Judeo-Christianity teaches a resurrection from death that will be conducted by the Creator, God Most High, and stresses dependence on him for eternal life. Occultism, on the other hand, teaches a resurrection accomplished through dependence on knowledge.
The phoenix is—at least in part—a symbol of this process.
Of Stars And Serpents
The choice of an avian mascot actually makes perfect sense because birds are creatures of the in-between. They possess the traits of spirits and reptiles simultaneously, and they occupy the space between heaven and earth.
* Scripture always describes spirits as fiery, and it calls them stars
Think about how royal people were depicted in the artwork of ancient cultures. Everywhere in the world, great rulers were portrayed alongside birds and winged snakes (and other winged beasts, and even winged solar discs). Their royal insignia usually incorporated something avian. This kind of imagery reflected a concept known as the divine right to rule. Many people-groups of the past embraced this idea that a kingdom's patron god indwelt or anointed each ceremonially crowned king. In Egypt, for instance, each new Pharaoh became the living embodiment of the god Osiris.
The winged serpent was a symbol of the gods of Egypt, Phoenicia, China, Persia, Mesoamerica, and others. In all instances, bird imagery was used in these places to indicate both divine beings and human spirits. This makes even more sense if you know that the highest orders of heavenly spirits have the semblance of serpents.
In esoteric thought, birds represent the connection of the corporeal world to the divine or supernatural realm. We need not dig deep to discover that this symbolism holds true even in the Bible, for the Ruach ha-Kodesh (Holy Spirit) descended on Y'shua in the form of a dove.
It may be interesting to note that during Creation Week, Elohiym created the great sea serpents and birds on the same day (Gen. 1:21). The two kinds just seem to go together.
The birds as symbols mediate between the physical and spiritual worlds, they reflect certain archetypal experiences encountered by the soul in its development through the alchemical process.
It has everything to do with it, actually. Alchemy is the process of taking something base and transmuting it into something lofty. This was primarily a spiritual pursuit to the ancient alchemists; the physical component of the craft was secondary. The fabled Philosopher's Stone of alchemy is the end product of a philosophical and pyschospiritual quest—it has nothing to do with metalurgy.
During an alchemical process in a laboratory, the original state of a targeted material is irreversibly lost, but that's okay because it becomes something better. Likewise, the spiritual alchemical process changes an individual from a profane to an enlightened state, according to occultists. It's not possibly to reverse the process and return to naivety. The spiritual rebirth of the alchemist (a.k.a. the Mystery initiate) must necessarily proceed from the death of the former life. The alchemist abandons his prior state of being willingly so that the new and better being can ascend.
Thus we have our first explanation of the meaning of the phoenix, and we understand why Manly P. Hall could say that the self-immolating bird acts as the sign of the initiate of the Order.