Here is an article from Grace Community Church's Pastor's Conference. It is about why expository preaching is so important.
Preach The Word: A case for expository preaching.
By Dan Dumas
Here is an excerpt from the article about what expository preaching is.
Richard L. Mayhue defines expository preaching as preaching that “focuses predominantly on the text(s) under consideration along with its (their) context(s). Exposition normally concentrates on a single text of Scripture, but it is sometimes possible for a thematic/theological message or a historical/biographical discourse to be expository in nature. An exposition may treat any length of passage.”
Preaching that is severed from the Scriptures is not Christian preaching!
“The regular proclamation of Christ through the close exposition of Scripture is more relevant in creating a worshipping and serving community than political causes, moral crusades, and entertaining services.”
Mayhue gives a helpful summary of the essential elements of expository preaching. They are as
1. The message finds its sole source in Scripture.
2. The message is extracted from Scripture through careful exegesis.
3. The message preparation correctly interprets Scripture in its normal sense and its context.
4. The message clearly explains the original God-intended meaning of Scripture.
5. The message applies the Scriptural meaning for today.
Richard L. Mayhue, Preaching: How to Preach Biblically