This is another one of those passages that doesn't necessarily use the word love - but implies such a vast supply that it warrants celebration.
It'd be easy to read this and briefly think that Paul is saying that our human frailty - that thing about us and in us that makes us need God so desperately in the first place - is to God our super power. Maybe Paul's even saying that God's power - can be manifest through us so mightily because we are fallen creatures, so prone to missing the mark, so apt to wander.
God's glory can surely be seen through heaven, angels, cherubim, seraphim, - or at least that's what I believe - though I've never seen any of that list. But through that list God's perfect holiness is made perfectly manifest. Through us on the other hand, God's grace is brought into focus unlike anywhere else in the universe.
It is embracing our weakness - in the full measure of humility we can that allows us to in real faith lean on God like never before. It's when we're most human - that God can be most God.
And He wants that for us.
As for His grace being "sufficient". Can I confess - that for a long time - every time I read this verse - in my bones - I felt like God was saying something akin to "my grace is enough for you to make do with" or maybe "you can eek it out with my grace".
But you know that's not really how God works is it? He doesn't give us barely enough of Himself to get by.
His grace is sufficient - because it's when we have these things about ourselves that bring us to the end of ourselves - the things that make us shake our head and fear the devil may win - that given over to Him - flings open the door to a vast store-house of every provision of character, grace and faith we could ever want ... far more, in fact, than we have the wherewithal to act on usually. What God calls sufficiency - we call extreme abundance. If God were promising us a drink of water with this verse - the image He'd attach to it - would be the Hoover Dam.
And the thing that God's offering in this sufficiency for is turning our "worst's" into opportunities for transformation.
How would your life be different if you woke up tomorrow morning with your character refined, advanced, strengthened, perfected? How long would it take your spouse, kids, friends, neighbors to figure it out?
If you wanted to get that without God - how would you do it? Where would you buy it?
This whole passage - from verse 7 all the way through 10 screams "See how much I love you!"
"Because of the surpassing greatness of the revelations, for this reason, to keep me from exalting myself, there was given me a thorn in the flesh, a messenger of Satan to torment me—to keep me from exalting myself! Concerning this I implored the Lord three times that it might leave me. And He has said to me, “My grace is sufficient for you, for power is perfected in weakness.” Most gladly, therefore, I will rather boast about my weaknesses, so that the power of Christ may dwell in me. Therefore I am well content with weaknesses, with insults, with distresses, with persecutions, with difficulties, for Christ’s sake; for when I am weak, then I am strong." NASB