When in the height heaven was not named,
And the earth beneath did not yet bear a name,
And the primeval Apsu, who begat them,
And chaos, Tiamut, the mother of them both
Their waters were mingled together,
And no field was formed, no marsh was to be seen;
When of the gods none had been called into being,
And none bore a name, and no destinies were ordained;
Then were created the gods in the midst of heaven
The first interesting aspect of this quote is that its opening, "When in the height" is actually what the words Enuma Elish mean in ancient Babylonian. When a work of art is titled the same way the text begins, the title is said to be an 'incipit.' This text explains the Sumerian polytheistic religion by saying that there are two gods who have always existed, a male and a female, married together. Eventually, other gods were 'called into being,' through the marriage of the two primordial gods.
The part of the text that says 'Their waters were mingled together,/ And no field was formed,' has been understood by historians and textual critics to be an explanation for the primordial state, namely that before the creation of the world, there was matter, but the matter was not arranged. Instead, the world was primordial stew, of sorts. Before there was reality, there was chaos.
Thus were established and were... the great gods.
But Tiamat and Apsu were still in confusion...
They were troubled and...
In disorder...
Apru was not diminished in might...
And Tiamat roared...
She smote, and their deeds...
Their way was evil...
This quote follows the accidental creation of the other gods. The primordial gods are said to be angered at the other gods, judging that the their deeds were evil (or alternately, the way the parents felt toward the children was evil—there are serious limitations in the analysis of the text because the text only exists in ancient fragments).
The point is that Tiamat and Apsu were set against their children, and also there seems to be a systematic difference between the waters of the parent gods and the natures of the children created. The orchestration of the story shows something elemental and fascinating about the human perception of reality. The myth seems to indicate that humans naturally understand that something must have come from nothing, that order must have been born out of chaos. This is why the text is religious in nature; it seeks to explain what kind of a force could explain reality. For the ancient Sumerians, the answer was found in the gods.
They banded themselves together and at the side of Tiamat they advanced;
They were furious; they devised mischief without resting night and day.
They prepared for battle, fuming and raging;
They joined their forces and made war,
Ummu-Hubur [Tiamat] who formed all things,
Made in addition weapons invincible; she spawned monster-serpents,
Sharp of tooth, and merciless of fang;
With poison, instead of blood, she filled their bodies.
This quote follows almost thirty lines of illegible text, but the consensus in academic communities is that Tiamat formed a coupe to overthrow her husband, Absu, either because she wanted to make an attempt on the throne, or because she felt pity for her children whom Absu wanted to kill. Tiamat, in the wake of Absu's defeat, summons godly forces and creates titanic, elemental beings to help her push for the throne. This can be seen as an extension of her nature: Tiamat, the goddess of the oceanic waters and all their depth and mystery, spawns sea creatures and serpents to help her attain her world.
But Marduk hath set out, the director of the gods, your son;
To set out against Tiamat his heart hath prompted him.
He opened his mouth and spake unto me, saying:
'If I, your avenger,
Conquer Tiamat and give you life,
Appoint an assembly, make my fate preeminent and proclaim it.'
This is the text where Marduk volunteers to fight against the forces of Tiamat, under the agreement that if he is to succeed, then he has earned his place as the king. To make his 'fate preeminent,' means that if he destroys Tiamat, he is to be above all the gods. This passage follows a description of another god failing to fight Tiamat, and Kingu, the new husband of Tiamat, taunting the other gods.
Then advanced Tiamat and Marduk, the counselor of the gods;
To the fight they came on, to the battle they drew nigh.
The lord spread out his net and caught her,
And the evil wind that was behind him he let loose in her face.
As Tiamat opened her mouth to its full extent,
He drove in the evil wind, while as yet she had not shut her lips.
The terrible winds filled her belly,
And her courage was taken from her, and her mouth she opened wide.
He seized the spear and burst her belly,
He severed her inward parts, he pierced her heart.
He overcame her and cut off her life;
In this passage, Marduk, the god of fire, sets a snare for Tiamat with lightning, and when his lightning electrifies her inward waters, a wind is created that pacified her, leaving Marduk able to kill her with his spear. The manner by which Marduk establishes his reign and kills Tiamat is to electrify her chaotic waters. The connection between this myth and the modern explanation for the origination of biological life on earth is uncanny. Also, this text has an ironic undercurrent, that the water god was destroyed by the fire god, instead of what would naturally be assumed, that water would win over fire. This reversal is what makes Marduk eligible to kill her and create nature as we know it.
Then the lord rested, gazing upon her dead body,
While he divided the flesh of the ... , and devised a cunning plan.
He split her up like a flat fish into two halves;
One half of her he stablished as a covering for heaven.
He fixed a bolt, he stationed a watchman,
And bade them not to let her waters come forth.
Marduk devises a plan to use the fallen body of the ocean goddess for his own purposes. He sets the blue waters of the sky into place by splitting her body and fashioning the top half of her serpent form to become the heavens. He sets a fire being (or lightening being) to guard over the division. This is the moment in the story when the conflict of the gods begins to 'explain' the natural world as it occurs. The sky is blue because Tiamat's body is made of water, and it's suspended above the world. The winds are the consequence of Marduk's electric net electrifying Tiamat. The stars are fashioned by Marduk, and Marduk establishes ancient cities, etc.