"Do not be afraid."  The scriptures make this announcement over and over again.  These are usually the first words out of angel's mouths.  Abraham, Moses, Mary, Joseph, shepherds tending their flocks, Paul sitting in a jail cell, the women looking for Christ's body at Easter and disciples rowing a boat in the strong wind all hear these words.  In all, these words occur almost 100 times in the scriptures.  Apparently, humans are very fearful creatures and we are in need of faith to function properly in the world.