Deuteronomy means “second law.” The book records Moses’ review of Israel’s history from the time they left Egypt up to when they stood ready to cross the Jordan river and take possession of the land God promised to them through Abraham, Isaac, and Jacob. So, we get a quick summary of all that has happened between Exodus and Numbers and including a lot of explanation of why it happened.
As God prepares Israel to enter the promised land Moses repeats for them the Ten Commandments and many of the details of the law that was given in Leviticus and Numbers. If you are paying attention you see the repetition of the covenant blessings and curses woven through this history review (see Leviticus 26).
God makes sure that Israel knows they are a chosen people (see chapter 6:20-7:11). God makes sure Israel knows they are chosen and not righteous. God warns them not to think the land and the blessing he gives them comes because they deserve it. He recounts for them the many, many times they rebelled. God is giving them the land because he chose them through the promise he made to Abraham and his offspring. God is progressively bringing about the fulfillment of the promise he made to Eve in Genesis 3:15 to bring through her offspring and then Abraham’s offspring the One who will ultimately defeat the evil one and make possible man’s return to the unrestrained presence and rule of God.
This is a pivotal moment in the history of Israel and in God’s plan of redemption, his chosen people are about to enter a new phase in their relationship with him. He is bringing them into a land where his blessing and rule are to prevail.
As Moses recounts everything, as all the history is remembered and the law repeated, one thing emerges as the most important thing:
“Hear, O Israel: The Lord our God, the Lord is one.You shall love the Lord your God with all your heart and with all your soul and with all your might. - Deuteronomy 6:4-5
I just skimmed back the first 18 chapters of Deuteronomy and no less than 14 times Moses warns Israel of the dire consequences of turning away from God and worshipping other gods. Every subject Moses addresses he connects to being faithful to God and to the covenant boundaries represented by the law, all of it rooted in worshipping God alone as God. Nothing matter’s more to God than his people remain his people.
I don’t think anything has changed.
And behold, a lawyer stood up to put him [Jesus] to the test, saying, “Teacher, what shall I do to inherit eternal life?” He said to him, “What is written in the Law? How do you read it?” And he answered, “You shall love the Lord your God with all your heart and with all your soul and with all your strength and with all your mind, and your neighbor as yourself.” - Luke 10:25-28