1. The message finds it 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. (12-13)There is one other important part of expository preaching worth adding. Expository preaching is both micro and macro. By this I mean that expository preaching is more than exegeting one subsequent passage after another. It involves careful exegesis of the micro text as well as placing that passage in its broader, biblical context.
There are two ways of doing this. The first is to pull back while in the middle of exposition. For example, why Jesus must go to the cross in Matthew 16 cannot be fully understood without tracing the history of atonement in Scripture. Also, the full meaning of the Lord's Supper cannot be explained without pulling back and looking at the metanarrative of the Exodus and the Jewish understanding of the perfect, spotless, atoning lamb. It is critical that the preacher exegete both the message and the broader biblical context.
The other way to do this is to dedicate an entire sermon to a broad metanarrative theme. An entire sermon explaining the meaning of "peace" or the Temple is a powerful and insightful way to preach. Once I dedicated an entire sermon on the theme of peace in order to introduce what Jesus said following his resurrection, "Peace be with you."
Overall, however, expository preaching is a direct application of one's view of Scripture. If all of it is inspired, then preach all of it without shame. If "the Bible is the cradle wherein Christ is laid" (Martin Luther), then preach Christ crucified from every passage.
That is what we mean by expository preaching.