This book describes the Pentecostal outpouring of the Holy Spirit in the twentieth century. It is the greatest revival in human history. It has touched millions of lives, reached across denomination barriers, restored spiritual gifts to Christian life, and permanently reshaped Christianity. The Pentecostal movement began humbly in a Kansas farmhouse and a shabby Los Angeles meeting hall. It spread rapidly throughout the U.S., spawning several new fast-growing denominations, and within a few decades had taken hold in every continent. Then, in the 1960s, even Pentecostal Christians were amazed when a neo-Pentacostal movement erupted in the mainline Protestant denominations and the charismatic renewal unexpectedly appeared in the Catholic Church. This book tells the whole dramatic story of God's Pentecostal work in our day--a day of great evil and--a day a great blessing.