"My Grace is Sufficient for You."

"My grace is sufficient for you, for my power is made perfect in weakness." 2 Cor 12: 7-9

I have always struggled to understand this passage. How can one be strong when one is weak? The whole passage reads:

Therefore, to keep me from being too elated, a thorn was given me in the flesh, a messenger of Satan to torment me, to keep me from being too elated. Three times I appealed to the Lord about this, that it would leave me, but he said to me, "My grace is sufficient for you, for my power is made perfect in weakness." So, I will boast all the more gladly of my weaknesses, so that the power of Christ may dwell in me.

The Messenger version reads:

I was given the gift of a handicap to keep me in constant touch with my limitations. Satan's angel did his best to get me down; what he in fact did was push me to my knees....then [God] told me, "My grace is enough; it's all you need. My strength comes into its own in your weakness."

Maybe if I deconstructed this, it would make more sense!