This volume is one in a series of wholly inde pendent volumes, which attempt to apply the prin ciple of evolution to the elucidation of spiritual truth. Of these there have already been published The Evolution of Christianity; Christianity and Social Problems; and The Theology of an Evolutionist. This volume seeks to employ that principle in the interpretation of the writings of the Apostle Paul. I hope to follow it with one or more volumes in application of the same principle in the interpretation of the other Biblical writers. Much if not most of the interpretation of Paul assumes that he entered on his ministry after his retirement in Arabia with a completed system of theology, that this system underwent no material change, that it was the same in his first preaching as at the end of his life, and is the same in the epistles to the Thessalonians as in the epistle to Colossians or the pastoral epistles; that, in brief, the various epistles are to be regarded as though they were different chapters in a book written at one time, by one and the same mind, in elucidation of the same system of thought.