2 Corinthians 12:9-10

12:9 But he said to me, “My grace is enough for you, for my power is made perfect in weakness.” So then, I will boast most gladly about my weaknesses, so that the power of Christ may reside in me. 12:10 Therefore I am content with weaknesses, with insults, with troubles, with persecutions and difficulties for the sake of Christ, for whenever I am weak, then I am strong.

2 Corinthians 13:3

13:3 since you are demanding proof that Christ is speaking through me. He is not weak toward you but is powerful among you.