Losing power is more than a simple inconvenience.  Not only does it shut down systems essential to our survival, it plunges us into darkness.  Real darkness can reduce confident strides to hesitant shuffles and relegate clear decisions to uncertainties.  A light shining in the darkness brings clarity, confidence, and hope in the darkness.  Sin has cast our world into spiritual darkness and our only hope is for a light from an otherworldly source to pierce the darkness and provide us with hope.  This light is the Prince of Peace who will one day administrate the perfect peace over the whole world.  Isaiah promises his arrival and urges the faithful remnant of his day and us that despite the darkness, we have reason to rejoice in Jesus Christ.