In the beginning when God created the heavens and the earth, the earth was a formless void and darkness covered the face of the deep, while the spirit of God swept over the face of the waters. (Genesis 1:1-2, NRSV)
The very first act of God as recorded in Genesis was to create order from chaos. The primordial chaos was formless and void. It had no shape nor could any part of it be differentiated from another. There were no opposites, no light nor dark, neither hot nor cold. This primordial chaos was typified by water which anciently was the one thing that had no set form. But in the midst of the chaotic primordial waters God created a space where order, and therefore life, could exist. God took the indistinguishable primordial chaos and differentiated it creating light and dark, day and night, springtime and harvest. The opposite of life was the formless void.
In our current popular culture order is equated with rigidity and invariance. Order is viewed as something that limits free will and is oppressive. But that kind of order is only the order that people impose on the world. The order provided by God in Genesis is the natural order that is the basis of life. Without the natural order, life would know nothing but chaos and corruption. Here is one of the major themes of Genesis. The natural order is created out of chaos, and from that order life is created.
The creation story in Genesis is crafted to show progressive spheres of order. On the outside of creation is where we find the primordial chaos without order. But beneath the dome of the sky there is a space created where life can exist because of the order created by God. Inside of this sphere is where we find world as we know it. And at the center of creation God created a garden as a perfect symbol of an orderly life. It was not wild untended garden, but well kept and full of all useful plants. The garden sustained life and at the center of the garden was the tree of life that gave immortality and eternal life.
But at some point corruption and it's resulting disorder and chaos enters the garden in the form of a serpent. But why a serpent? Here is where our modern culture fails to understand the symbolism here. Suppose I am telling a story and it is about a young girl who wears a red cape with a hood and she is walking through a forest. Just based on that, who does she meet in the forest? Does she meet a goat? Or a troll? Or a fairy? No, she meets a wolf. Why does she meet a wolf and not a bear, or perhaps a family of bears with papa bear, mama bear, and baby bear?
We know that she will meet a wolf because in our culture we have that story ingrained in our collective understanding. We can do this with many other stories. A story of three little pigs, what do they do and what happens to them? A story starts out with a tortoise and a rabbit, what will happen? A girl with long hair lives in a tower, what will happen? We know the answers to these questions because we have been taught them by our culture.
So in the story of the creation where God brings order to chaos, who will come to corrupt the order created by God? Here our culture fails us because we are not surrounded by the milieu of the ancient world. If we weren't steeped in our culture it would seem strange that three little pigs were building houses and why they used three different building materials. In the same way it seems strange to us that a serpent comes into the well ordered garden to corrupt it. But in the ancient world it was something generally understood and to be expected.
In the mythology of the Middle East the serpent was the symbol of the primordial chaotic waters. In Canaanite and Hebrew stories a serpent is the agent of chaos and evil. The Babylonian goddess Tiamat was the goddess of the sea and from her the world was created, and she is frequently described and depicted as a dragon or a serpent. The symbol of a serpent, especially a sea serpent, as an agent of chaos and evil can be found throughout Indo-European mythologies. From Norse mythology to Persian mythology, and almost everywhere in between, a serpent or a dragon represents evil, destruction, and death and in many cases is associated with water, the sea, or destructive storms. So the symbol of a serpent entering into the garden to tempt our first parents to bring death and corruption would have been readily understood by people anciently.
The effect of the serpent in the Garden of Eden was to bring corruption which would ultimately result in death. In this way the cosmic principle of order and life are contrasted with corruption and death. Without God the cosmos is chaotic and devoid of order and life. God brings order to the chaotic darkness and from that life can exist. But the world is not completely ordered. Corruption and death are fundamental parts of the world. We ourselves are corrupt and because of that we are cut off from the the orderly garden of life and the presence of God. We will die because of the inherent corruption found in the world.
In the temple endowment we symbolically go through the process of seeing order and life created in the world. We are introduced into the garden. We are expelled from the garden out into the corrupt world where we will experience sorrow and death. To return to the presence of God and gain eternal life we must have the order of God restored to us. This is something we cannot do by ourselves. Through ministering angels God reveals to us the Holy Priesthood, after the Order of the Son of God, which order is necessary for us to return to the presence of God. Just as God created life in the world by bringing order to the chaos, it is only through the Order of the Son of God that we can remove corruption and chaos from our lives and gain eternal life.