Galatians 4:8 Formerly, when you did not know God, you were slaves to those who by nature are not gods. 9 But now that you know God—or rather are known by God—how is it that you are turning back to those weak and miserable forces? Do you wish to be enslaved by them all over again? 10 You are observing special days and months and seasons and years! 11 I fear for you, that somehow I have wasted my efforts on you.
Acts 26:24
And as he thus spake for himself, Festus said with a loud voice, "Paul, you are out of your mind! Your great learning is driving you mad."