Deuteronomy 1:41, 43 Then ye answered and said unto me, We have sinned against the Lord, we will go up and fight, according to all that the Lord commanded us. And when ye had girded on every man his weapons of war, ye were ready to go up into the hill…So I spake unto you; and ye would not hear, but rebelled against the Commandment of the Lord, and went presumptuously up into the hill.
In fear and unbelief and in direct rebellion against God’s command Israel had earlier rebelled and refused to go up against the giants in the land. Then that generation was not allowed to enter at all. Afterward, they changed their minds, confessed their sin, and decided to go up on their own. This decision was against God’s will, for He told them, “Do not go up and fight, for I am not with you.”
But the people would not hear, rebelled, and went presumptuously. Of course, they were driven back and defeated, because the Lord was not with them. The lesson of the Conquest is clear: with the Lord, we can do all things; without the Lord, we can do nothing. Philippians 4:13: “I can do all things through Him who strengthens me.” I am too weak (being blind, dead, and an enemy of God) to do anything against the overwhelming spiritual forces of evil. I cannot by my own reason or strength even believe in Jesus, but the Holy Spirit calls me by the Gospel.
We are so full of pride and unbelief that we presume that we can do good things on our own. So we are tempted to believe in our own good life, good character, and good works to overcome sin and evil and find God. But God is not with us until we come to believe in Jesus Christ as our Lord and Savior. Then, under Joshua (the Hebrew name for Jesus) we conquer the Enemy and live in the Kingdom.