The Babylonian Creation was twofold. The first creation was the product of a plenum, and describes a hail of impossible animals tumbling out of it, with features and limbs which were interchangeable, resulting in some creatures which were utterly fantastic. The creation is from a plenum, because all the characteristics of living creatures are already present, though the way these characteristics are distributed is the stuff of nightmares. This first creation was without reason and rational order, and chaotic.
We are also told that the creatures shared each others features. This is another characteristic of a plenum. All things can pass into everything else. Nothing is fixed. The initial state of the world does not have fixity of any sort.
Were the gods already present? Some of them were, at least in a sense. The Babylonians had the idea that they could call gods into existence, by naming and describing them, and performing ritual which set them up in the Babylonian Heaven.
There is a curious aspect to the Babylonian creation story, in that the god Marduk, who became the head of the pantheon of Gods, and was the defining power for the organisation of the second creation, was said to have been ‘held prisoner’ during the time of the first creation. This imprisonment can be understood in at least two ways. First of all, if Marduk had been active at the time of the first creation, why would he have allowed its irrational nature? Therefore it was decided that the explanation for his inaction was that he was not free to act. A second interpretation of his imprisonment may be that the initial irrational creation was inevitable, and had to happen before it was possible to establish good order. Something about the first creation resulted in his release and his presence.
In either case, the idea of the plenum is indicated, and in its most pure form.
The gods in the Babylonian creation story are indicative of abstract powers and properties, and some of them have reality before the advent of the second creation. Anshar, is King of Heaven for example (in fact he has no name as such, since An Shar is the description ‘King of Heaven’. It is important to know what he is). The Babylonian Heaven is clearly the underlying plenum, where all things are present as potencies, so Anshar is the abstraction of the potency of the plenum. In the complex narrative of the liturgy for the New Year Festival, Anshar is father to Marduk, but Marduk is also presented as the equal of Anshar. In fact as Anshar himself. Marduk is also the equal of other important gods representing abstract ideas in the earliest times of the creation.
Description of these early gods natures, associations, and actions is a way for the Babylonians to discuss and understand the nature of the plenum from which the gods emerged. What Marduk eventually became as head of the Babylonian pantheon, described in the passage in the liturgy known as 'The Fifty Names of Marduk', is the totality of the powers of Anshar and the other gods, and therefore signifies that Marduk embodies the character of the underlying pleroma.
After Marduk established control, and began to call the other gods into existence, these later gods now represent something like a human understanding of the world, and how it might be made. The gods represent in abstract form the good things in human life and social organisation. Each god is represented as an aspect of Marduk and his exemplification of good kingship. Thus the gods names and descriptions indicate that he supplies places of refuge for man, the cultivation of crops, the provision of quays and landings for trade, the maintenance of good order in the world, and so on.