"...it remains a document of incalculable value for the beginnings of Christianity. ... The rise and progress of Christianity is a study beset with problems, but some of these problems would be even more intractable than they are if we had not the information of Acts to help us. For example, how did it come about that a movement that began in the heart of Judaism was recognized after a few decades as a distinctively Gentile religion? ... [Luke's] narrative is, in fact, a source-book of the highest value for a significant phase of the history of world civilization."