"On the theological side, the dominating theme of Acts is the activity of the Holy Spirit. The promise of the outpouring of the Spirit, made by the risen Christ in 1:4, is fulfilled for Jewish disciples in chapter 2 and for Gentile believers in chapter 10. ... The book might indeed be called ‘The Acts of the Holy Spirit’. ... He is the principal witness to the truth of the gospel. The supernatural manifestations which accompany the spread of the gospel signify not only the Spirit's activity but also the inauguration of the new age in which Jesus reigns as Lord and Messiah."