As Lawrence points out, his book is a practical tool for pastors. In many respects, though, Biblical Theology is also useful for every believer, because we are all called to be "theologians": thinking rightly about God.
In Chapter One Lawrence begins a discussion of a method of interpreting Scripture so that we can be reasonably assured that we are understanding the meaning of Scripture. Whatever method we use, our system of interpreting Scripture is called "hermeneutics."
Lawrence states the fundamental principle that we as readers of the Scripture text can understand what God is saying to us in it, and that there is a correct meaning: not what the text "means for you," or what it "means to me," but, simply, what it "means."
The method Lawrence proposes is the "grammatical-historical method," a key component of which is the understanding that we are not -- primarily -- seeking to understand what a particular word means, but what a sentence means, as the author originally intended it. Though understanding words is important, "context is king," and we ignore the context in which the word is found at our own peril.
An important component of the grammitcal-historical method is recognizing the different genres in Scripture -- poetry, history, prophecy -- because how we arrive at "units" of teaching and preaching will depend in part on what sort of genre we are dealing with. For instance, a unit of teaching from the epistles will be much shorter than a unit of preaching from the book of 2 Chronicles.
Lawrence gives a brief description of the way to interpret each genre, for which he gives seven categories. Though a serious student of Scripture will want to explore more thorough treatment of interpreting each of the genres, Lawrence's summary is a good illustration of the importance of recognizing Scripture genres before we set about the task of interpretation.
Giving the example of teaching a group of sixth grade boys in Sunday school, Lawrence demonstrates that every believer -- given the proper exegetical tools -- can rightly understand Scripture, in a way that comforms us into the image of Christ.