These past several weeks, I’ve had to take a number of plane trips, and this meant I’ve had a fair amount of time for reading. I managed to get through a lengthy book that I had been eager to read: Christianity’s Dangerous Idea: The Protestant Revolution by Alister McGrath. Dr. McGrath is a professor of theology at Oxford University and one of the most prolific authors on the religious scene today. His latest book is a very readable exploration of the history of the Protestant movement from its origins in the sixteenth century to the present day, as well as a study of the major themes of Protestant thought and practice. In the course of his text, we find rich discussions of Martin Luther’s master idea of justification by grace through faith, and of John Calvin’s doctrine of double predestination, and of the general Protestant option for the primacy of the Word of God. But the issue to which McGrath returns again and again, almost obsessively, is that of authority. Who, for Protestants, finally has the authority to offer the correct interpretation of the Bible?