This verse was spoken to us during the prayer meeting this past Tuesday. It didn't make much sense to me at first; I understood the first two verses... but the last verse about carrying around death in our body so that life might be revealed... didn't really click. But I just realized that God clarifies what He meant later in the same letter:
"But He said to me, 'My grace is sufficient for you, for My power is made perfect in weakness.' Therefore I will boast all the more gladly about my weaknesses, so that Christ's power may rest on me." - 2 Corinthians 12:9
Why do we need so many humblings? Why do we need so many valleys? These struggles are God's way of showing us our weaknesses. And He doesn't do it just for the sake of rubbing it in our faces; it is when we realize what we cannot do on our own that we look to God for grace. There are so many hardships in the Christian walk-- many that nonbelievers do not have to endure. But God's grace is sufficient for His people! Every weakness, fear and pressure is a venue for God's grace to prove sufficient.
Let's even rejoice that we are deemed worthy of such suffering, that God would provide so much opportunity for Christ to be revealed. God's grace is sufficient for you!