2 Corinthians 12:6-7

12:6 For even if I wish to boast, I will not be a fool, for I would be telling the truth, but I refrain from this so that no one may regard me beyond what he sees in me or what he hears from me, 12:7 even because of the extraordinary character of the revelations. Therefore, so that I would not become arrogant, a thorn in the flesh was given to me, a messenger of Satan to trouble me – so that I would not become arrogant.