The 10th point of the Scout Law is "A Scout is Brave." Bravery takes many forms.
It means physical bravery--standing up in spite of our fear to a challenge. In combat it means keeping your head when shots are firing around you. In Scouting it may mean climbing a rock wall even though you might be uncomfortable with heights.
It means mental bravery--doing the right thing even when our flesh screams to do something else. Telling your folks you broke the vase in the dining room even though it would be easy to blame it on the dog or a younger sibling. Telling a Scout buddy it's not right to make fun of another Scout. Those thinks are hard, but they are the right thing to do.
It means spiritual bravery--studying your Bible and praying and telling people about God and Jesus Christ even when we don't feel like it (especially when we don't feel like it). As Christians this should be easy for us because the power of the Holy Spirit is in us. But too often we don't call on that power to help us.
So a brave man isn't just the guy who throws himself on an enemy grenade; it's the guy who gets up every day and does the things required of him by God, his family, his boss, and his nation.