Magic Forums

So I am an agnostic. I don't really believe in any kind of God or Goddess but I like to keep my mind open to them. I have been studying magic for about 2 years and in every book or source I've read they all seem to have one thing in common, the use of deities in rituals, spells etc. If magic is just the science and art of changing the world around you using your own will to manipulate energy why do so many sources talk about invoking deities? Since magic is the manipulation of the fundamental energies around us are the deities perhaps suppose to be some kind of manifestation of this energy?

I hope I don't sound too ignorant but I am very curious to see what you have to say about it.

-Adam