Revival- Do it Again, Lord!

Over the last few weeks and months, the word revival has been thrown around by various groups of Christians, and even in the media. From the gatherings at Asbury University to the new release of the movie "Jesus Revolution,” revival is in the air. However though, many are confused or even skeptical when it comes to the topic of revival. Is it real? Is it necessary? What does the Bible have to say about it?