What is the biggest weakness people have?

Undoubtedly, the biggest weakness people have is simply being human. Whether it is acting in our own best interests, or controlling a minor weakness (such as control over food intake), or not believing in ourselves to reach a major goal (or to even try), people stand in their own way. If we can clear away all outside obstacles, the only obstacle left is our own faith in ourselves. Without faith, there is no hope. Without hope, there is no action.