Deuteronomy 1:32-33 But even after all he did, you refused to trust the Lord your God, who goes before you looking for the best places to camp, guiding you with a pillar of fire by night and a pillar of cloud by day.
The Israelites didn't trust God. God had brought them to the Promise Land where bunch of grapes had to be carried on a pole. God had parted the sea before them and they still didn't trust God. They looked at the giants of that land and measured those giants against their own strength and not God's strength. So they refused to go in!! A whole generation of people lost out because they didn't trust in God.
We don't have a pillar of fire by night or a pillar of cloud by day, but we do have our Bibles and we have the Holy Spirit inside of us guiding us. What do we miss out on when we don't trust God? How many people do our decisions effect when we don't trust God? We can read the story of how the Israelites didn't trust God and wonder why...then miss out on opportunities to trust God ourselves because we size up a situation on our abilities instead of God's abilities.