There are a great many people who constantly wonder why we are having all this fuss about the theory of evolution. Many think it a shame that professing Christians should engage in such an unseemly quarrel as is now going on between the Fundamentalists and the Modernists. These lovers of peace are ready to become indignant at both parties. They inquire, Is not the present controversy worse than useless and quite contrary to the spirit of Christian harmony and good will? This war in the churches seems to them of the same order as the late war among the nations, and almost as disgraceful to our modern civilization. But there are genuine reasons for the present situation. And the reader's attention is invited to a brief study of these reasons throughout the following pages. The common notion that the crux of the whole difference between the Fundamentalists and the Modernists lies in their opposite attitudes toward the theory of organic evolution is not wrong. But the general public is wrong on two very important points. It is wrong in supposing that this difference of attitude toward the theory of evolution is concerned chiefly with the theory of man's origin from the lower animals by natural development. This is partly true; but such a statement of the problem really evades or covers up the chief point at issue after all. The religious problem connected with evolution is primarily the problem of sin, which has been and always will be the greatest problem confronting mankind. The fact of sin cannot be denied; as G. K. Chesterton remarks, it is a fact as practical as potatoes. It is as undeniable as the dirt on one's face or the rent in one's coat. The problem arises when we attempt to account for it, or when we try to find a remedy for it.