Moses assured the Israelites that God will give them the conquest of Canaan. He warned them three times lest they presume that their righteousness provided sufficient merit for their success. Moses had already told them that their future success would be guaranteed “because” of their obedience to the commandments. The people of Israel might naturally assume, then, that success was an indication of their own righteousness.
We might be prone to make a similar mistake. A pastor with a successful, growing congregation might assume that he is in God’s favor because of the numbers. A businessman who lands a lucrative contract may suppose that he is being rewarded for his godliness. In both cases, the assumptions may be correct, but there might be other factors at work not at all related to one’s personal righteousness.
Moses stressed three times that “it is not because of your righteousness that the LORD your God is giving you this good land to possess, for you are a stubborn people” (Deuteronomy 9:6). He went on to rehearse the sin of the golden calf and the incidents in the wilderness that provoked God to anger. He recounted how he fasted on their behalf and pleaded for their forgiveness. He retold the story of how God, in His mercy, relented, and did not punish them as their deeds deserved. If not for Moses’ intercession and atonement on their behalf, Israel would not have even survived the journey from Egypt. They had Moses to thank for their deliverance thus far. There could be no talk of their merit and righteousness. Their observance of the Torah was not sufficient to merit the conquest of the land.
If the children of Israel did not deserve to take possession of the land, why did God give it to them? Moses gave two reasons: The sin of the Canaanites and the covenant promises to the patriarchs.
It is not for your righteousness or for the uprightness of your heart that you are going to possess their land, but it is because of the wickedness of these nations that the LORD your God is driving them out before you, in order to confirm the oath which the LORD swore to your fathers, to Abraham, Isaac and Jacob. (Deuteronomy 9:5)
For the promise to Abraham or to his descendants that he would be heir of the world was not through the Law, but through the righteousness of faith. (Romans 4:13)