How to prepare a sermon – part 4


Step 4: Nail it down

At this stage in sermon prep I have lots of loose threads that need to be brought together to get a handle on what direction the sermon is going to take. It is important now to nail down what the passage is actually teaching so that the wood is not missed for the trees. This step aims for clarity and consists of two parts: checking your work with commentaries and nailing down the Big Idea.

Checking the Commentaries

A good commentary primarily helps you to understand the biblical text. To this end, I limit myself to two commentaries for each book of the Bible – one technical and the other devotional/expository. A technical commentary focuses on exegesis of the biblical text by examining the text in its original language (mostly the Hebrew Old Testament and Greek New Testament), as well as its grammar and syntax. Examples of good, evangelical technical New Testament commentaries are the New International Greek Testament Commentary (NIGTC) series, the New International Commentary on the New Testament (NICNT), or the Pillar series. For the Old Testament commentaries, I have appreciated titles from the Word Biblical Commentary series and the New International Commentary on the Old Testament (NICOT).

A devotional or expository commentary spends less time on the original text but instead focuses on its meaning. Such commentaries are often (but not always) sermon series that have been edited into written format. These types of commentaries are usually shorter in length than their technical counterparts but the good ones are no less profound. I recommend titles from the Bible Speaks Today series or the Tyndale commentary series, both available on every biblical book.

The point of using commentaries here and not at the beginning of my sermon prep is to check what I have already studied and get help answering any questions that arise from the text. The danger of reading the commentaries too soon is that they can replace the important step of thinking and praying through the passage, resulting in an over-reliance on someone else’s views, rather than my own. It’s not that a commentator’s views of a passage are going to be wrong (they are the work of biblical specialists after all) but that their comments may skew my own conclusions prematurely.

The Big Idea

This is the clincher. We come to the Big Idea. The Big Idea aims to express the meaning of the passage in a succinct form – usually ten words or less. Haddon Robinson calls it ‘the 2AM test’ – the idea that if someone woke the preacher up the night before his sermon and asked him what the is sermon about, he can express it in a short and clear sentence.

Nailing down the meaning of the passage helps to cut through the multiplicity of notes that I’ve taken in the run up to this step and clarify the core teaching. If you cannot express the meaning of the passage in ten words or less, you don’t have sufficient grasp on it yet.

I find that it takes a few goes to get a decent Big Idea that I’m happy with. My first attempt might be 20 words long, so I try to reduce to 15. And then to 10 or less.

The Big Idea should sum up in a nut shell what the passage is teaching. It is not simply descriptive. ‘Joseph gets sold into slavery by his brothers’ is not a good Big Idea – this only describes what is happening (Genesis 37:12f). Instead, ‘God always fulfils his purposes, even through innocent suffering’, moves beyond description to the point that the passage is getting to. (If you think there is no sign in this passage of God fulfilling his purposes, look at the final verse, Genesis 37:36!)

Here’s a couple of other Big Ideas from sermons I have preached recently:

  • The inevitability of God’s work brings assurance, thanksgiving and prayer (Phil 1:1-11)
  • The household is to model gospel transformation to the world (Titus 2:1-10)
  • God’s salvation comes through human weakness (Judges 6:36-7:18)

No Big Idea is perfect but it is helpful at giving clarity (both to the preacher and ultimately the listeners) and helps to communicate the core truth. This is not to say that a Big Idea has to include every piece of teaching a passage includes, nor that it is the final word on that passage. However without a Big Idea, the sermon is likely to wander all over the place and the congregation will find it difficult to connect with. Better a clear, central thought that is expounded rather than a rambling collection of the preacher’s thoughts from his reading that week.


For additional resources on choosing the right commentary, consider