Fifty years ago Ralph Winter spoke at the Congress of World Evangelization in Lausanne, Switzerland. He laid out a vision of world evangelization that transformed the perspective on the unreached not as countries or nations, but ethnic people groups. What progress has been made in global evangelization since that moment? What does the remaining task look like? Matthew and Ted interview RW Lewis, who has researched and published a booklet called The Great Progress of the Gospel and the Remaining Frontier Missions Task.