My gorgeous BFF beat me to writing about this word somehow... So here is her take! Thanks !!!
The smallest part or particle imaginable; a bit; a jot; an iota; -- generally used in an adverbial phrase in a negative sentence. "Samuel told him every whit." --1 Sam. iii. 18. "Every whit as great." --South. [1913 Webster] So shall I no whit be behind in duty. --Shak. [1913 Webster] It does not me a whit displease. --Cowley. [1913 Webster]
The expression "If God can use a donkey then surely he can use me" is something I heard often growing up. You may ask how I can associate this memory with the word "whit". The answer is quit simple. God can use any flicker or fragment I think I am if I allow him to do it by whit. Another meaning of the word "whit" is whole or complete. This comes from the Greek word "holos" and is used in the New Testament twice in John 7:23 and John 13:10. So if I allow God to use me wholly he will take a little nut shell and use it to change lives.