Summary: Only God can (and does) meet our needs. He does this for the purpose of displaying the gospel in our lives.
32Jesus called his disciples to him and said, "I have compassion for these people; they have already been with me three days and have nothing to eat. I do not want to send them away hungry, or they may collapse on the way." 33His disciples answered, "Where could we get enough bread in this remote place to feed such a crowd?" 34"How many loaves do you have?" Jesus asked. "Seven," they replied, "and a few small fish." 35He told the crowd to sit down on the ground. 36Then he took the seven loaves and the fish, and when he had given thanks, he broke them and gave them to the disciples, and they in turn to the people. 37They all ate and were satisfied. Afterward the disciples picked up seven basketfuls of broken pieces that were left over. 38The number of those who ate was four thousand, besides women and children. --Matthew 15:32-38 (quickview)  (NIV)
God understands our needs
When we are in need, when we lack something that we consider to be essential to our happiness and well-being, our first temptation is to think that God has forgotten about us; that He is unaware or unconcerned about our welfare. This is especially true if the need is longstanding.
So when we pray (if we pray?), our prayers take on a petulant, complaining tone. Instead of praying, "God, please meet this need," it’s "God, why aren’t you meeting my need?".
* "God, the car broke down again this morning. How am I supposed to get to work? Why can’t we have a dependable car? I need a car. Why aren’t you taking care of me?"
* "God, the kids need new shoes again. I don’t know where I’m going to get the money. Kids’ shoes are so expensive! What am I supposed to do? God, are you there?"
* "God, why don’t I have a husband? Don’t you care that I’m still single?"
We may pray repeatedly, not because we have faith that God will answer, but for a different reason: either we are impatient or we are worried that perhaps He isn’t listening. We nag.
* My children do this sometimes. "Dad, I’m hungry. Can I have a granola bar and juice?" "Dad, where’s my granola bar and juice?"
* Or when a birthday is coming up: "I want a remote control car for my birthday." "Can I have a remote control car for my birthday?"
* Sometimes wives [and husbands] do this. Why? They’re just not sure that they’re getting through, that they’re being heard. She’s not convinced that their husband really comprehends how essential it is that he fix the toilet. And the noncommittal grunts that she receives when she brings it up are not reassuring.
But [verse 32] tells us that when God doesn’t provide what we feel we need, it isn’t due to a lack of caring or a lack of knowing. It may be because our understanding of our needs is inadequate. Perhaps He has something better in store for us. It may be because the timing isn’t right. It may be because God wants to develop patience or faith. It may be for reasons we can’t understand. But we don’t need to nag or badger Him to get His attention. He knows and He cares.
And when you pray, do not keep on babbling like pagans, for they think they will be heard because of their many words. Do not be like them, for your Father knows what you need before you ask him. - Matthew 6:7-8 (quickview)  (NIV)