Christianity as not only a world-religion, but pre-eminently the world-religion, can be rationally appreciated only in the light of its origins. The nineteenth century, therefore, to which nothing was understood that had not been understood genetically, devoted its newly won methods of historical criticism to a comparison of the contemporary documents, the Pauline Epistles, with Acts, the earliest embodiment of the tradition, that it might learn the facts of the great evolution of the Church from the Synagogue. But inquiry into the story of the second founder of our faith was, from the nature of the case, a mere preliminary to the deeper inquiry into the story of its first Founder.