Mathew 4:4 

But Jesus replied, “It is written and forever remains written, “Man shall not live by bread alone, but by every word that comes out of the mouth of God.”

Everything God did on this earth He spoke into being.  He had the bible written down so we could also speak His words.  That is how we live the word of God by speaking it and calling those things that be as not as though they were.  Yes, food keeps us alive, but the word of God makes us thrive and overcome.