Not necessarily. Do whatever works for you.

The advantage of writing out a full manuscript before preaching a sermon (whether or not you take that manuscript into the pulpit) is that writing is the evidence of thought. Writing down everything you intend to say will sharpen your thoughts and force you to be clearer and more precise than you would have been otherwise.

Different preachers will develop slightly different ways of preparing sermons, which is fine. Do what works for you. That said, here are some steps that should be involved in the preparation of any expositional sermon.

Do no application. Expositional preaching is preaching that takes the main point of a scriptural text, makes it the main point of the sermon, and applies it to life today. Good expositional preaching will apply the text specifically: to different kinds of people in different spiritual states and different situations in life.

Some people today claim that expositional preaching is irrelevant for postmodern people. “People today need narrative and conversation and dialogue and drama! They don’t need expositional preaching.”

In fact, expositional preaching is particularly relevant for postmodern people:

Some people resent expositional preaching’s monological mode. One man stands up for many minutes and preaches while everyone else listens. Isn’t this unfair or even oppressive? What about conversation? Certainly, there should be plenty of venues in the life of the church for conversation, whether through inductive Bible studies, follow-up sermon studies in small groups, or other contexts. 

No, expostional preaching is not the only kind of preaching a pastor should do. But…

Yes. Some of these are more distant historical precedents and some of these are clear examples of expositional preaching—preaching that explains and applies the main point of a biblical text.