And when the Lord sent you out from Kadesh Barnea, he said, “Go up and take possession of the land I have given you.” But you rebelled against the command of the Lord your God. You did not trust Him or obey Him.
In this chapter Moses is recounting all of the times Israel had rebelled against God and disobeyed Him. Here Moses is reminding them of the time when they refused to enter the promised land because they feared what their spies had seen telling them, namely that they could not conquer the land because of the size of the inhabitants and their armies. All except Caleb and Joshua, none of the other spies had any confidence they could succeed.
As a result they wondered for 40 years in the wilderness. Moses explained this in Numbers 32 to the leaders of the Gadites and Reubenites who did not wish to cross the Jordan river
10 The Lord’s anger was aroused that day and He swore this oath: 11 ‘Because they have not followed Me wholeheartedly, not one of those who were twenty years old or more when they came up out of Egypt will see the land I promised on oath to Abraham, Isaac and Jacob— 12 not one except Caleb son of Jephunneh the Kenizzite and Joshua son of Nun, for they followed the Lord wholeheartedly.’ 13 The Lord’s anger burned against Israel and he made them wander in the wilderness forty years, until the whole generation of those who had done evil in his sight was gone.
Moses would add after today’s verse
You have been rebellious against the Lord ever since I have known you.
He felt this so strongly that as Israel prepared to cross the Jordan he assured them of victory against the Anakites because God would subdue them, but warned them about their self-righteousness.
4 After the Lord your God has driven them out before you, do not say to yourself, “The Lord has brought me here to take possession of this land because of my righteousness.” No, it is on account of the wickedness of these nations that the Lord is going to drive them out before you. 5 It is not because of your righteousness or your integrity that you are going in to take possession of their land; but on account of the wickedness of these nations, the Lord your God will drive them out before you, to accomplish what he swore to your fathers, to Abraham, Isaac and Jacob. 6 Understand, then, 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 stiff-necked people.
God is the source of all of our blessings, whether we choose to acknowledge Him or not. The consequences of not acknowledging Him or obeying His commands can be devastating. For the nation of Israel the time they refused to trust Him and cross the Jordan resulted in no one over the age of 20 entering the promised land 40 years later except for Caleb and Joshua.
Our price for not accepting the free Gift of Grace will not be 40 years of wandering in the wilderness, but something much much worse – eternity in hell.