Joshua 7:10-12

In this passage Israel fails to defeat Ai. The reason for their failure is laid out here. In this case it is sinfulness that prevents them from walking victoriously. In this case God tells Joshua to get up and go deal with the sin. There's no need for him to sit in misery before the ark the thing that needs to be done is to get rid of the sin. I think this is possibly the case in life for us. We fail so much because we carry so much sin. The things that God desires for us to do become impossible because we're not walking right. We need to watch out for sin that creeps in on our lives. It can be hidden and take investigation to find. Once it is found it needs to be dealt with. Not just in repentance, but in "get up" action.