Deuteronomy completes the books of Moses, and being a fifth book of Scripture, is a review of Israel's history and of the laws given them, with more detailed explanations and application of the law, thus reminding us of the judgment seat of Christ at the end of our wilderness journey.
Three major divisions will be helpful, In our study of this book. The first, ending with Chapter 4:43, is a resume of Israel's history. The second, from Chapter 4:44 to Chapter 30:20, is an explanation and expansion of the laws previously given to Israel. The third (Chapter 31 to the end) is mainly prophetic, though chapter 34 is necessarily added by a different writer, for it records the death of Moses. It may have been Joshua or Eleazar the high priest who wrote this, but we have no need to know.
Not only is Moses the writer of Deuteronomy, but he gives the record of what he spoke to Israel in this book. The instruction is not addressed to the priests as much of Leviticus is, and some of Numbers also, but to all Israel. for in the summing up of our history each of us individually must give account of himself to God (Romans 14:12), therefore each is responsible to take to heart the truth God gives in His Word for our welfare in our earthly history.