The Revival that Shook the World - How the Holy Spirit Moved

One revival that shook the whole world more than any other came in Scotland in the 1820s.  No other revival spurred on a larger worldwide missionary movement like this one.  The waves hit Asia, Africa, Oceania, and South America with a force that is still being felt to this day. What are the precursors to such revivals?  Could this world still see Holy Spirit fire like this again?  Kevin Swanson discusses this great event in missionary and church history with Dr. George Grant.