Light was caused to exist without the presense of the sun, or stars, as these items he created later. This leads me to wonder if the "light" which was brought forth is the light of which we think, as the light we assume is meant is that which comes from the sun. If the sun did not yet exist, where did this light come from, and is it what we think it is?
Light (as I define it for the purpose of this discussion) is much more than the visual spectrum we can see. Nearly every form of energy falls somewhere within the electromagnetic spectrum, including sound. Energy itself is, essentially, light. Energy is also the building block and foundation of everything. As scientists are able to see smaller and smaller particles of matter, they are learning that the very smallest particles are little bubbles of energy. AKA, little bubbles of light...
That initial creation of light/energy flooded the universe with this most basic building block, in its many forms. Visible light, X-rays, sound waves, and most importantly strings of light energy.
I envision the creator, having brought this "light" forth begins, over the next five days, to weave it into shape and form. Bringing strings together to form elements, to bring elements together to form molecules, to bring molecules together to form earth and air and water. Creating the universe like a tapestry from threads of light.
If it is correct that light and energy are one and the same, the concept is made even more interesting in the formula of E=mc².
We would be restating energy as light, in such, saying that light equals mass times the speed of light, squared. This means that a quantity of light in a given mass is determined by its own speed. It is fortunate that the speed of light is a constant, otherwise things would grow infinitely more complicated. Infinite is all too appropriate, as if the speed of light were not constant, the quantity of light would grow infinitely as its speed increased.
The speed of light is a constant so we do not have this complication to worry about.
Another bit of scientific information is that energy can neither be created nor destroyed, only changed from one form to another, or stored and released. This means that light, being energy, also can neither be created nor destroyed.
So, energy (light) is omnipresent - it is the base construct of all things and permeates everywhere, which means light is everywhere and in all things. Light exists outside of time - the speed of light is a constant, it does not accelerate or decelerate, it just is. It is indestructable, it has no beginning and no end. Because light is omnipresent, were it sentient it could also be considered all knowing because it is all places at all times and therefore omniscent.
Omnipresent, omnipotent, omnitscent. What does that remind you of?
God, perhaps? The idea is that energy/sound/light/heat itself IS God*, and that the most miniscule component of our makeup - quarks/strings of light-energy - are threads of God's very being. All of us, all of matter, all of existance combines to make the whole that is God, one giant matrix of energy living with a tremendous sentience that allows existance to persist. It is a huge concept to grasp, it may make your head spin to realize that God is not some being that is "out there" somewhere, but rather that God IS the finite, and the infinite, the macro and the micro, the alpha and the omega...this is starting to sound familiar...
*I also believe that there is much more to light/energy than we are aware of or can measure - and that God is much more than JUST light/energy.