This book is about that treasured doctrine of Pentecostalism: baptism in the Holy Spirit, understood as a work subsequent to conversion to Christ. Since the British theologian James Dunn's publication of his influential work Baptism in the Holy Spirit, there has been heated response from Pentecostals in defense of the doctrine. Key players are Roger Stronstad, Howard Ervin, David Petts, James Shelton, Robert Menzies, and ex-Pentecostal Max Turner. This book reviews Pentecostal criticisms of Dunn with respect to Luke-Acts, concluding that Pentecostals are right: for Luke, receiving the Spirit was not the inception of new covenant life. It was a powerful enabling for prophecy and miracles; for the church's outward mission and its internal life. After placing Luke-Acts in a wider canonical context, the book closes with some practical lessons from Luke-Acts for today's Pentecostal churches.