We are called out of darkness into HIS marvelous light.  Why do we let the enemy, who comes to kill, steal, and destroy, keep us in darkness?  I cannot see in darkness, but yet I crave to be able to see.  I know He instructs us to count it all joy, even in times of trouble, James 1:2.  Here in Peter, he tells us to declare the wonderful deeds of Him.  So, whenever I find myself slipping into darkness, one of the first things that comes to mind is to praise Him.  Soon I begin to see the light once again and miraculously things begin to clear up and I can see.  

2:9 But you are a chosen race, a royal priesthood, a holy nation, God's own people, that you may declare the wonderful deeds of him who called you out of darkness into his marvelous light.