The book of Deuteronomy was traditionally viewed as a group of sermons delivered by Moses to the tribes of Israel just before they were to enter the Promised Land. As such it can be viewed as the appeal of Moses as to how the Israelites should conduct themselves once they take possession and settle in the Land  .
Although a very neat and convenient view the historical scope, authorship and theological significance of the Book extends far beyond this narrow view. Davidson describes the Torah  , of which Deuteronomy is a central part, as ‘like a great medieval cathedral, hundreds of years in the making…you will see…different architectural styles’.  This provides the backdrop to the subsequent discussion of the provenance. He makes the point that Moses could not have written his own obituary and it is reasonable to assume a mixed authorship.
On the purpose front, Deuteronomy is one of the four most quoted books in the New Testament.  It was, in particular, a favourite of Jesus both when He was expounding true ethical behaviour in the Sermon on the Mount and answering the question ‘what is the greatest commandment?’  posed by the ultra-orthodox religious leaders of His day. In light of this enthusiasm of Jesus for the Book and later the apostle Paul when establishing basic theology  , it can not be dispensed as with being applicable only to the ancient Jews at a particular point in history.
Both these thoughts will be examined more closely below.
The historical dating of the contents of the book vary from c1000B.C.-400B.C. Some commentators prefer to narrow the start period to c621B.C  and others, notably of the liberal tradition, would prefer to see Deuteronomy as part of the deutero-canonical history extending far beyond 400B.C. 
Large portions of the book seems to be strongly connected as the origin of the reforms instituted by King Josiah in 622B.C.  and a particular group of scholars would say it was at this point that it was recognised as part of the Jewish canon. It was the ‘Book of the Law’ found in the temple.
Clements  proposes that there were edits and insertions at this point as a consequence of Josiah’s reforms and that the context of the rest of the first five books can be considered “post” or “pre” Deuteronomy. Hastings et al. make a similar point in that the apostasy, then collapse, of the Northern Kingdom with the consequent migration of the Yahwehists  south necessarily meant there needed to be a reconciliation with the predominantly Elohist  tradition of the South  .
Blair  proposes a second phase of editing may have occurred after the return from the Babylonian exile (c550A.D.) where a second spiritual reformation was seen to be necessary. This model is generally attributed to the work of the Graf-Wellhausen school of critics. Conservative schools only admit to minor editing asserting that Moses would have been the major author.
There needed to be a cultural update of the Hebrew scriptures in light of their experience to make it available once again to the people without changing the Mosaic creed  . The catastrophic collapse of the Northern Kingdom and its apostasy is suggested by Cunliffe-Jones  as to be a possible explanation as to the severity of the punishments and broad use of capital punishment found in Deuteronomy. It was meant to be a warning to the newly unified nation not to repeat the mistakes of the previous generations.
The repetition of themes between Exodus, Leviticus, Numbers and Deuteronomy alongside the grammatical mixing of the tenses  within the same passages is good evidence that there was a substantial editing process as the ethnic groups within the nation rediscovered their common history. The sometimes strange insertion of a group of laws in a seemingly unrelated passage also supports this merging of the two creeds.
There is substantial disagreement amongst scholars as to the internal structure of the book beyond there being an original framework document with subsequent edits. Thus, there is substantial variation as to how they would choose to present the divisions. This is partially explained as to whether the author is trying to draw the historical divisions or the key theological messages from the book.
Blair  proposes the following broad theological divisions:
1. First address (ch1, v1- ch4, v43): Moses reminding the nation as to what God has done for them.
2. Ch 4, v44 - ch28, v68: meaning and obligations of the covenant relationship;
3. Ch 29, v1 – 30, v20: what God proposes for Israel. A renewal of the covenant.
4. Final chapters announcing the change of leadership to the nation from Moses to Joshua.
Clements  prefers the broader historical divisions of 1-11, 12-26 and 27-34 with each section representing a framework document that has been edited and enhanced in the editorial stages. As such he highlights:
1. Elaborations of the work found in Exodus, e.g. Deut 5,6-21 and Ex 20, 2-17;
2. Moses’ fairwell speech (chs1 and 34) represent the preface and postscript.
Much more granular divisions and analysis can be found as reported by Hastings  et al but these are broadly in line with the overall message as delineated by Blair and the principles of a framework document as seen by Clements.
Blair  comments that Deuteronomy is not a book of the Law in the narrow sense of a Bill of Parliament. Likewise Charpentier  remarks that the legal component is interpolated with interpretation and emotional appeals for the people to meditate and discover the God beyond the form of the religion:
“For this commandment which I command thee this day is not hidden from thee, neither is it far off…But the word is very nigh unto thee, in thy mouth, and in thy heart, that thou mayest do it.” (Deut, 30, vv11,14)
Blair summarises, in a fashion reminiscent of the exhortations of the Apostle Paul, Peter and the writer of Hebrews, the message as “remember, obey, behold”  :
1. Remember what He has done;
2. Obey the statutes and commandments from the heart;
3. Behold the rewards and glory of what God has for His chosen.
Paul, in writing to the Galatian church referred to the “Law” as the “schoolmaster”  . The vivid thought here is that the Law is to instruct and inform as well as to educate. A central purpose of the Deuteronomy is not only the historical purpose for Israel but a timeless spiritual message disclosed to all mankind. 
Some criticism has been levelled at the harshness of the legal code. Both Clements and Cunliffe-Jones comment on the harshness of punishment and the apparent racism calling for the genocide of the previous inhabitants of the land.  However, with the benefit of hindsight, historical and archaeological evidence, Price  makes the case that the utter depravity of the residents of the land including their habitual child sacrifice and perverse sexuality was such that it would be deadly to Israel’s culture and society.
Hastings et al  and Blair  outline some of the religious reforms and theological concepts found in the text:
1. Re-establishment of exclusive worship of Yahweh;
2. One place to worship, Jerusalem;
3. Abolition of all endemic pagan practices, e.g. child sacrifices, sacred prostitutes, divination and magic;
4. Laws regarding property and the administration of justice;
5. The practical outworking of loving your neighbour;
6. Evaluation of a daily life with respect to the ‘unclean and the clean’.
This is a very deep anti-thesis to religious practise common throughout the world that relegates ‘religion’ to a building or a day.
7. The coming of the Messiah or Christ (ch18, 15-22);
8. God is God of the whole Earth and all peoples (ch6v4, 9,v5, 10v14, 32v8).
He is the ultimate arbiter and has the right of ultimate judgement. Cunliffe-Jones underlines that later prophets such as Isaiah, Amos, Hosea and Micah are clearly influenced by this teaching. 
9. The people of God are made aware of their position and privilege (ch26-28);
10. The importance of the transmission of faith to the younger generation.
The vast scope and influence of Deuteronomy can clearly be seen. It is seen to be diverse in parts and chronology and may easily be misinterpreted as overly brutal or racist. However, a closer reading reveals a potent theological message that remains deeply relevant for both Jews and Christians as to the morality of their God.
Its wider message to society and the world may be summarised in a remark from Cunliffe-Jones which is itself a quotation from an early commentator: ‘to go with God is life and to go against God is death’  . In the words of Deuteronomy itself, God is setting before all people their choices and the consequences of those choices. If people isolate themselves from God it is to their destruction.
This is not because God is standing ready with fire and brimstone but it is demonstrating the spiritual truth that the only source of life is God’s life. To disconnect from God is to connect with death. This finds echo again and again in the New Testament teaching and is undeniably the foundation for New Testament theology.
Word Count: 1520 words (excluding footnotes)
 Blair, Edward P., The Word Illustrated Bible Handbook, p118, Word (UK) Ltd, 1988.
 Meaning literally ‘The Law’. The first five books of the Bible known also as the ‘Books of Moses’.
 Davidson, R., A Beginner’s Guide to the Old Testament, p35, Saint Andrews Press, 2001.
 Blair, op. cit., p118.
 Matthew 22, 36.
 For example, Galatians 3.
 Cunliffe Jones, H.E., Deuteronomy, p14, BS1275.2.C8.
 Hastings, Grant, Rowley (eds), Deuteronomy in Dictionary of the Bible, pp213-216, 2nd Edition, J & J Clark, Edinburgh, 1963.
 2Ki. 22:3-23:25
 Clements, R.E., The Book of Deuteronomy, pp7-12, BS1275.3.C45
 With the traditional centre of worship at Shechem.
 With the traditional centre of worship at Jerusalem.
 Hastings, op. cit., p215
 Blair, op. cit., p119
 Clements, op. cit., pp9-10.
 Cunliffe-Jones, op. cit, p15.
 Charpentier, E., How To Read the Old Testament, p56, SCM, 1982
 Blair, op. cit., p119.
 Clements, op.cit, pp7-12
 Hastings, op.cit. pp213-215
 Blair, op. cit. p118
 Charpentier, op. cit., p56
 Blair, op.cit. p119
 Galatians 3,24
 Cunliffe-Jones, op. cit. p15
 Cunliffe-Jones, op. cit. p15
 Price, R., The Prophecy of Noah, part of a tape series published by Chichester Christian Fellowship, 1979. Roger was an exquisite, scholarly, didactic expositor of biblical passages.
 Hastings et al, op. cit., p216
 Blair, op. cit., p120
 Cunliffe-Jones, op.cit. p28
 Cunliffe-Jones, op.cit. p29