Let's go back to the context where this verse appear, 2 Cor 12:10
- 2Co 12:10 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 verse is the encouragement that we can accomplish all things, against all odds, in spite of our weaknesses and inabilities, because of Christ's empowerment, to glorify God. It is the victory of seemingly weaklings due to Christ's power inside. It remove the excuse that we cannot because we are weak. We can be confident that God who call us to will also empower us to His accomplish will with Christ that is already given to us. Praise be to God and our Lord Jesus Christ, we are strong and we are more than conqueror. I can accept my weakness and limitations and know that they are not limiting me as long as Christ is calling me to do His will. After the experience, I am sure we have the weaknesses.
Many famous preachers suffered from speech deficiency in all sorts but they nevertheless through Christ become great preachers.
I think the best interpretation for this verse is in the Message Bible. "It was a case of Christ's strength moving in on my weakness. Now I take limitations in stride, and with good cheer, these limitations that cut me down to size—abuse, accidents, opposition, bad breaks. I just let Christ take over! And so the weaker I get, the stronger I become."
The verse is not an excuse for our lack of doing but should be an encouragement and confidence for us to act. Ps 27 has a passive form of saying this, because of Christ, I have no fear of evil, danger, what man or army may do to me. I am assured of His protection and I shall dwell with Him.