One of the questions I had on the use of the church calendar is this. It seems that it would be impossible to preach expositionally with a calendar. I mean at best, the exposition of a few chapters of book, but not all the book. Isn't preaching through the entire book a part of expository preaching. If expository preaching is impractical in the practice of the church calendar, then how can anyone claim that the church calendar gives balance.
Well, see here is the problem... What is one's accepted definition of "Expository Preaching"? It is probably the case that most people understand the term as referring to a "verse-by-verse" approach. I am not one of them.
My working definition of "Expository Preaching" is the "expounding" on a particular text/passage of Scripture with appropriate application. Therefore, one could preach a topical series, or a thematic series, etc. vs. preaching through an entire book or chapter systematically.
Okay, in regard to observing the Church Calendar, I'm agin it for various reasons, the main one being much of the calendar isn't warranted biblically. Secondly, you should NOT preach on the Church Calendar nor any other man-made document, e.g., it is customary in the more traditional Dutch Reformed churches to preach through the Heidelberg Catechism during the evening worship service. This to me is absolutely unbiblical. I have had some rather 'hot' discussions with a number of pastors who adhere to this 'tradition' and suggested that their responsibility is to PREACH THE WORD and not a catechism. My suggestion has always been to select one of the proof texts of the creed, confession or catechism and preach on that.