How was God going to give Israel the land of Canaan?
God planned to drive the Canaanites out Himself, using hornets or whatever means, removing the population while leaving everything intact. Israel would then simply walk in and take over the land under God's blessings. They only needed to go in and possess it, but unbelief caused them to send spies instead.
Les explains that God had a system where He would literally remove the Canaanite population but leave everything intact, so all Israel had to do was walk in and take over with God's blessings. He compares it to a bomb that kills people but leaves everything intact. God said, 'Go in and take it.' But in unbelief they asked to send spies, so God condescended. If the spies had returned with a positive report and the people had gone in, God would have let them; it was a valid offer. They did not because of unbelief.