When Moses told these words to all the people of Israel, the people mourned greatly. And they rose early in the morning and went up to the heights of the hill country, saying, “Here we are. We will go up to the place that the LORD has promised, for we have sinned.” But Moses said, “Why now are you transgressing the command of the LORD, when that will not succeed? Do not go up, for the Lord is not among you, lest you be struck down before your enemies. For there the Amalekites and the Canaanites are facing you, and you shall fall by the sword. Because you have turned back from following the LORD, the LORD will not be with you.” But they presumed to go up to the heights of the hill country, although neither the ark of the covenant of the LORD nor Moses departed out of the camp. Then the Amalekites and the Canaanites who lived in that hill country came down and defeated them and pursued them, even to Hormah. (Numbers 14:39-45 ESV)
Whereas before their fear and failure to trust Yahweh led them to proclaim that it was impossible to take Canaan and that they would die and their children would die, now they foolishly, irrationally, decide on their own that they should attack. Despite Moses’ warning that Yahweh is not with them, they go up and fall into the hands of the Amalekites and other Canaanites in the hill country.
When we rebel against God by not trusting in Him and obeying Him it leads to the most ridiculous of behaviors and beliefs. How much more sane it is to trust in Him. Do we think that we can overturn His decision on how to deal with us? Does repentance not bring with it a willingness to listen to God? But this was not real repentance. This was the lunacy of unbelief. Lord, protect us from our own folly.