John 16:4

4 But these things have I told you, that when the time shall come, ye may remember that I told you of them. And these things I said not unto you at the beginning, because I was with you.

Ver. 4. Ye may remember, &c. ] And act, what I have foretold and taught you. The difference between divinity and other sciences is, that it is not enough to know, but you must do it; as lessons of music must be practised, and a copy not read only, but written after. Non est haec umbratilis philosophia, sed quae ad usum et praxin aptanda. (Calvin.)