Parasha Re'eh, starting on Deuteronomy 11:26, begins the final set of instructions given by Moshe to the people he has led for the past 40 years. If we read the rest of Deuteronomy as a simple restatement of the Torah, we will completely miss the point of what is happening here. The rest of this last book of the Torah is far more than the final reminder of a loving parent sending his child off to camp - "Remember to brush your teeth, change your sox every day, mind your manners,..."
To understand what is going on, we must first understand that there are three distinct economies for the nation Israel - and so also for all of the children of God. These economies are characterized by the nearness of God and by how He interacts with His people. These three economies are:
In the wilderness, God is visibly present in the camp. By day there is a pillar of cloud and by night a pillar of fire. Bread falls directly from heaven; water flows from a rock; a messianic figure (Moshe) is always there to speak for God and sin is dealt with very quickly.
Things are different when Israel is in the land. God is not directly visible, food is gotten in the normal way by sowing and reaping; prophets speak for God; the consequences of sin are still direct, but they are delayed. Whereas in the wilderness fire came down from heaven, the earth opened beneath rebels' feet or a plague swept through the people, in the land sin typically brought drought or oppression by foreign people.
Finally, exile is characterized by the hidden face of God. Here things seem to operate by chance - indeed one of our largest industries is insurance based on actuarial tables. In exile it becomes very easy to ignore God or even to deny His existence.
With the above in mind, consider who Moshe is addressing with his final instructions. These are people who have lived in a Type I wilderness existence all of their adult lives. Most were born in the wilderness and so have no experience with anything else. Even those who were under 20 at the time of the exodus have never lived in the Land of Israel. Their experience, 40 years in the past, is of a Type III exilic existence.
Far from being a simple restatement of information found elsewhere in the Torah, Deuteronomy is a concise expression of what is required to thrive in the Land. It is literally a roadmap and instruction manual for a people stepping off into the unknown. That is why there is such an emphasis on the problems with idolatry. When entering a new place, it is natural to take a look at how the natives have coped with the problems you are about to encounter - we like to learn from the experience of others. Moshe says in no uncertain terms not to study the ways of the natives. His message is that although pagan worship may seem to work, it ultimately leads to exile and death.
In that, considering the rise of new age worship in the church, Moshe's message is very relevant for us today.