"Then was Jesus led up of the Spirit into the wilderness to be tempted of the devil. And when he had fasted forty days and forty nights, he was afterward an hungred. And when the tempter came to him, he said, If thou be the Son of God, command that these stones be made bread. But he answered and said, It is written, Man shall not live by bread alone, but by every word that proceedeth out of the mouth of God." -Matthew 4:1-4
i love this passage; it so clearly points out what faith is! Jesus has the power to do whatever He wills; walk on water, turn water into wine--He could've even come down from the Cross if He desired. He certainly has the power to turn a few stones into bread, so why not do it? in essence, that would quell satan's tempations and Jesus (Who is God in the Flesh) would still remain perfect, in that He's all-powerful and unlimited (the limitations of this world are nothing to Him, as they are everything to us; He is from above, we are from below). theoretically, He could've performed another miracle to be recorded in Scripture and shown as a victory against the devil in a way that would have been unprecidented, but He didn't. why?
"Therefore I take pleasure in infirmities, in reproaches, in necessities, in persecutions, in distresses for Christ's sake: for when I am weak, then am I strong." -2 Corinthians 12:10
one of my favorite Biblical figures, Paul, sums it up nicely i think in Corinthians. after asking God three times to take away a 'thorn in his flesh', which is alluded to but never made explicitly clear in Scripture as to what it actually is, God basically tells Paul 'My Grace is sufficient for thee', to which Paul replies with the verse posted above. i love this answer! it's so... enlightening, really! the solution to a problem ('problem', from our perspective only) isn't necessarily to remove it, but to act with it and even through it! in other words, weakness isn't weakness, it's strength! consider this passage:
"Then Jerubbaal, who is Gideon, and all the people that were with him, rose up early, and pitched beside the well of Harod: so that the host of the Midianites were on the north side of them, by the hill of Moreh, in the valley. And the LORD said unto Gideon, The people that are with thee are too many for me to give the Midianites into their hands, lest Israel vaunt themselves against me, saying, Mine own hand hath saved me. Now therefore go to, proclaim in the ears of the people, saying, Whosoever is fearful and afraid, let him return and depart early from mount Gilead. And there returned of the people twenty and two thousand; and there remained ten thousand. And the LORD said unto Gideon, The people are yet too many; bring them down unto the water, and I will try them for thee there: and it shall be, that of whom I say unto thee, This shall go with thee, the same shall go with thee; and of whomsoever I say unto thee, This shall not go with thee, the same shall not go. So he brought down the people unto the water: and the LORD said unto Gideon, Every one that lappeth of the water with his tongue, as a dog lappeth, him shalt thou set by himself; likewise every one that boweth down upon his knees to drink. And the number of them that lapped, putting their hand to their mouth, were three hundred men: but all the rest of the people bowed down upon their knees to drink water. And the LORD said unto Gideon, By the three hundred men that lapped will I save you, and deliver the Midianites into thine hand: and let all the other people go every man unto his place." -Judges 7:1-7
i know that's quite a bit to read, but i encourage you to do it. Gideon here is told by God that he is to lead isreal to fight the Midianites, but before he does, God tells Gideon not once, but twice to lessen the number of soldiers set to go into battle with him; finally God says in verse 7 that 'by the three hundred men... will I save you'. what a perfect example of what Paul was speaking of when he said 'for when i am weak, then am i strong'! God wants us to realize our weakness in order to show us His strength (which is even referred to as 'being made perfect in weakness' in Scripture), as well as showing the rest of the world that even though we are nothing, God can accomplish something with and through nothing.
this all being said, God doesn't need weakness to make His strength known. i believe one of the deepest messages we can take from Paul and the story of Gideon is that regardless of our perceived notions of strength and/or weakness, God is still in power; we cannot move outside of this fact. again, this points back to what i said in my first post; faith is me admitting to God that 'i cannot'; it's not something i 'have' towards Him, or me 'believing enough' in Him. rather, faith is me accepting that 'God is', therefore i have no choice but to believe! the truth is the truth whether or not you accept it.