
I was surprised in 1 Cor 10:10 where Paul said some people had said about him, "His letters are weighty and forceful, but in person he is unimpressive and his speaking amounts to nothing." And then in 1 Cor 11:6 Paul says, "I may not be a trained speaker, but I do have knowledge."
I think we all can find comfort and encouragement in the fact that even someone as powerful and impactful in God's kingdom plans as Paul may not have been the best, most polished public speaker... but God used him anyway!