There is the quote for all to see...light is not the only form of energy. While it is true that E=mc^2, and C is the speed of light, not all energy is light. Depending on the atom and the energy levels, the energy released when an electron drops to a lower energy level can manifest itself as UV rays, visible light, x-rays, gamma-rays, radio waves, and all other forms of radiation. Electrons are easily excited with the addition of heat, which is not the equivalent of light, but is obviously still energy. So, in conclusion: energy can exist without light, as adrianxw pointed out, not all life is traced back to photosynthesis, and it is entirely possible and plausible that life would exist without light. Indeed, as Adrian pointed out, it happened. So, the quote stands.
"Atheism turns out to be too simple. If the whole universe has no meaning, we should never have found out that it has no meaning: just as, if there were no light in the universe and therefore no creatures with eyes, we should never know it was dark." - C.S. Lewis