I found the first and last chapters to be the most helpful.
Perhaps I had missed this in other reading, but Carrick explores the nuances of the indicative-imperative as found in Scripture, especially in Paul's letters. The indicatives are the great objective facts of Scripture - what God has done in creation and redemption as well as who we are in Christ. The imperatives are the great commands of Scripture - repent and believe, present your body as a living sacrifice.
According to Carrick, there are two sets of indicatives with two sets of imperatives that are interwoven between them.
Indicative #1 - What God has done in salvation - the objective truths (e.g. the Apostles' Creed)
Imperative #1 - How we are to subjectively respond to the objective facts - repent and believe.
Indicative #2 - Having been born again, you are a new creation - you are justified and adopted. You are now a child of God (before, you were a child of wrath).
Imperative #2 - Now that you a co-heir with Christ, you are to flee temptation, resist the Devil, pursue holiness and righteousness.
Essentially, all four of these elements are necessary for solid, consistent expository preaching. They must be stressed in order and with balance. Imperative #2 is to follow Indicative #2 not precede it.
Also, he tackles the challenging problem of redemptive-historical preaching verses exemplary preaching. They are only fully biblical when in relationship to each other based on the four elements. Without all four, there is an unhealthy imbalance on either quietism or works-righteousness.