From the time of Moses until the death of Jesus, Israel’s history revolved around that Old Covenant, the law of Moses. Israel’s relationship with God was defined by their obedience or disobedience to Moses’ commands. Sadly, most generations of Jews strayed far from God. As a prophet, Moses had foreseen this tendency and sternly warned against it.
[God said of the Israelites,] For when I have brought them into the land flowing with milk and honey, which I swore to give to their fathers, and they have eaten and are full and grown fat, they will turn to other gods and serve them, and despise Me and break My covenant…. [Moses said to the Israelites,] For I know how rebellious and stubborn you are. Behold, even today while I am yet alive with you, you have been rebellious against the LORD. How much more after my death! … For I know that after my death you will surely act corruptly and turn aside from the way that I have commanded you. And in the days to come evil will befall you, because you will do what is evil in the sight of the LORD, provoking Him to anger through the work of your hands. (Deuteronomy 31:20, 27, 29 cf. The Song of Moses in Deuteronomy 32)