Jesus answered him, saying, "It is written, 'Man shall not live by bread alone, but by every word of God.'"
Man shall not live by bread alone ...  Important as physical needs assuredly are, man is spiritual, and not merely physical; therefore, if man should take a forbidden course in the fulfillment of his physical needs, without regard to his spiritual nature, he forfeits life in the highest and best sense.  The passage cited here was  Deuteronomy 8:3.  Materialism concerns itself only with bread; but God never intended this to be the exclusive goal of humanity.