That is why, for Christ's sake, I delight in weaknesses, in insults, in hardships, in persecutions, in difficulties. For when I am weak, then I am strong.
NIV
So for the sake of Christ, I am well pleased and take pleasure in infirmities, insults, hardships, persecutions, perplexities and distresses; for when I am weak [in human strength], then am I [truly] strong (able, powerful in divine strength).
AMP
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.
KJV