1st and 2nd Aliyot:
Moshe instructs the Chosen People to eradicate any remnant of idolatry and strengthen all aspects of service to G-d. All offerings must be brought to the "Chosen" place, the Beit Hamikdash, so that worship is an act of humility and selflessness, rather than a self-indulging "need". An even greater danger to our uniqueness is the innate desire to compromise and assimilate Torah values with other forms of worship. (the Chanukah bush syndrome)3rd and 4th Aliyot:
Moshe forewarned the Jews against incorporating any pagan practices, and against the false prophet, idolatrous missionaries, and the Ir Hanidachat – the Apostate City. These must be destroyed along with their material belongings. When using the world in accordance with the wishes of the Creator, we declare the existence of a Creator who has a divine purpose for creating the material world. When we misuse the physical in the service of "gods who are not G-d", we negate the Creator's purpose for creating the universe. Therefore, they and all their belongings must be destroyed.5th, 6th, and 7th Aliyot:
The remainder of the Parasha, details those Mitzvot that set us apart from all other nations: Kashrut; Maasrot – Tithes; the Sh'mitah – sabbatical year; the laws regarding lending money; the Eved Ivri – a Jew who is a slave; the consecration of the first born animal, and a review of the main Yamim Tovim – holidays: Pesach, Shavout, and Succoth.
Rav S.R. Hirsch points out that Rosh Hashana and Yom Kippur are not reviewed in Sefer Devarim because there were no changes in the practices of those Yamim Tovim when living in the desert or living in Eretz Yisrael. (Intro. to Divarim)