Hitherto in the development of our thought, we have been considering the Christian Gospel as an entity set in the midst of a progressive world, and we have been studying the new Christian attitudes which this influential environment has been eliciting. The Gospel has been in our thought like an individual who, finding himself in novel circumstances, reacts toward them in ways appropriate alike to them and to his own character. The influence of the idea of progress upon Christianity, however, is more penetrating than such a figure can adequately portray. For no one can long ponder the significance of our generation's progressive ways of thinking without running straight upon this question: is not Christianity itself progressive? In the midst of a changing world does not it also change, so that, reacting upon the new ideas of progress, it not only assimilates and uses them, but is itself an illustration of them? Where everything else in man's life in its origin and growth is conceived, not in terms of static and final creation or revelation, but in terms of development, can religion be left out? Instead of being a pond around which once for all a man can walk and take its measure, a final and completed whole, is not Christianity a river which, maintaining still reliance upon the historic springs from which it flows, gathers in new tributaries on its course and is itself a changing, growing and progressive movement? The question is inevitable in any study of the relationship between the Gospel and progress, and its implications are so far-reaching that it deserves our careful thought.