I stumbled on to Theological Roots of Pentecostalism during a visit to Wesley Theological Seminary in Washington, DC  in 2006. Donald Dayton received an award from the faculty that day and he preached in the chapel on the many faces of Wesley. Later, I bought copies of this book and another of his books, Discovering an Evangelical Heritage.
Theological Roots of Pentecostalism appealed to me because I had recently become acquainted with a Pentecostal mission evangelizing Muslims. I was intrigued by the different style of worship and by the dedication of the evangelists that I met who were Pentecostals. I wanted to learn more about them.
Dayton raises 4 points that were insightful.
- The Four Square gospel is very different. He describes a Pentecostal as someone who sees Christ as savior, Baptizer of the Holy Spirit, healer, and coming King (173). A typical Presbyterian confesses Christ only as Lord and Savior.
- The Pentecostal reads the books of Luke and Acts with special interest (especially Acts 2). The hermeneutic used is devotional (23). Essentially, each verse should be read as if the words “in my life” were appended to it.
- The discussion of the Latter Rain movement was thought provoking. The basic idea is that the gifts of the spirit were especially prominent during the the Apostolic period and would also reappear in the latter days. The reference to Joel 2:28—And it shall come to pass afterward, that I will pour out my Spirit on all flesh; your sons and your daughters shall prophesy, your old men shall dream dreams, and your young men shall see visions. Even on the male and female servants in those days I will pour out my Spirit. (Joel 2:28-29 ESV)—the recent active participation of women in ministry is accordingly taken to be a sign of the Second Coming of Christ.
- Dayton links the switch among American evangelicals from Post-millennial to Pre-millennial eschatology to a profound discouragement with following the Civil War. The approaching end was signaled, not by progress, but by decline (163). This transition is important in explaining the attitude towards evangelism and service that we see today. Those waiting to be raptured (beamed up) have less incentive to promote reform than those preparing the world to receive the coming King.
Christians owe a debt of gratitude to the Pentecostal movement which many people date to the 1906 revival on Azusa Street in Los Angeles, California . The Pentecostal movement began with an outpouring of the Holy Spirit which touched all races, ethnic groups, and genders from its inception and it has spread worldwide. If it were not for the Pentecostal movement, the number of Christians in the world would have declined in the 20th century, much like their numbers have in the United States.
I enjoyed this book. Its take away points are likely to color my view of Pentecostals for a long time. I would recommend it to Christians curious about Pentecostalism and interested in the history of religion in America.
 Professor emeritus, Northern Baptist Theological Seminary (www.Seminary.edu).