I know it may seem a trivial thing and there are those who would vehemently disagree with me but this drives me nuts.
I tell them, "That will get you a job one day! Mark my words." It means that you care about the English language just a wee bit more than perhaps someone else does. It means that you are precise in what it is you are trying to express. It may mean a deeper appreciation of English grammar in general, which will reflect positively on your place of employment.
It is extremely important when you are speaking on behalf of the Church. Words mean very specific things in everything from ethics to rubrics. One careless word can throw things into a tailspin.