Imagine how weak he was at the end of the 40 days fast! When satan came to tempt Him, it must have been tough for him to say no.
"You're so weak from hunger. You're practically straved to death! You want food? Bow down to me, satan, and I'll feed you. The Father doesn't care about you, or he wouldn't have made you go through this. He would have made sure you had food and water if he really loved you! Come on, I'll take care of your needs even though your Father has neglected you. All you have to do is acknowledge that I'm stronger and better than your Father."
Jesus must have known that his earthly body was in bad shape from going without food or water that long. He was probably on the verge of death! But He still wouldn't give in to the doubts satan was planting in his mind. Is God really my Father? Is God really good? If He is, would He have asked me to go through this much suffering?
Instead, Jesus answered: "It is written: Man must not live on bread alone, but on every word that comes from the mouth of God." Not only did Christ not ask satan for bread, He still gave glory to God!
So when we lack something, when we are hungry and helpless, when the suffering is great and the temptations are barely bearable, we must follow Jesus's example, and not only turn away from satan's solutions to our problems, but give our faith and glory to God.