2 Corinthians 12:10 KJV
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.
This chapter is taken up with concern that the preacher should remain humble. Paul gave reason both at the beginning and the end for being "exalted above measure". Doubtless he could have thought more highly of himself than he ought, except that he strove for humility and God provided tools to accommodate it.
Here Paul concludes, "when I am weak then am I strong." I take it that his strength must have been accepted by faith because, had he seen his strength, then he would not have known his weakness.
Paul is, without a doubt, the most influential man in the world after Christ. Yet Paul would never have known that.
May those God uses the most greatly never suspect it to be so.