As 'whatever' moved over the 'deep'.. then he 'said' "let there be light" - according to one book..
This denotes something moved over that which was deep. Who created the depth?
More importantly, how did 'whomever', 'SPEAK'?
Who or 'WHAT' heard his commands?
Who or What granted his wish's?
The foundation for getting a clear picture of this, has to do with understanding sound, and the nature of the universe. And the start of such understanding might be through what is written below.
All vibration is sound. Radio waves, and light waves, are sound. How can this be? It has to do with the universe being way more complex that anyone has dreamed.
Keep in mind parallel universes, side by side, in the MEGA-universe. Also, keep in mind that the words being used are so that the layman can get a picture. They are not for technical mathematics.
"Space" is an elastic solid. It is home for, possibly, an infinite number of "parallel universes, side by side," each one operating with its own "universal" vibration.
When you move something physical through a section of space, like waving your hand in the air, the individual sub-atomic particles that make up the individual atoms of your hand, are broken down and reassembled across multitudes of universes, causing reactions in all these universes. The actual sub-atomic particles are points - think of eddies in a pond, created by two or more waves crossing over each other - where the various parallel universes "touch" momentarily, all of this acting according to UNTOLD MULTITUDES of EXTREMELY COMPLEX universal laws.
Such things as light, sub-atomic particles that move through space, electromagnetic waves, are all simpler forms, similar to the complex ones listed in the previous paragraph. ALL vibrations through space - because space is an elastic solid - are, therefore, sound.
When you have a Being that is essentially, in His nature, from "outside of" our mega-universe (whatever that means), and One Who has the ability to cause vibrations in the "space" of our universe that might be compared with vibrations that people speak through the air - although the vibrations through the air are many magnitudes less complex than speaking through the elastic solid of space - you can start to see how the things of the universe were spoken into existence, as written in the first chapter of the Bible.