We are so accustomed to the use of the word in a spurious sense that we are slow to apprehend the immense significance of this human energy which lies potentially within us. Unfortunately trained young folks and scientifically minded people are apt to shy away from the word and put themselves on the defensive, as though they were about to be asked to believe the impossible or the dubious or the unprovable. Faith in the sense in which St. Paul uses it does not mean _believing_ something. It is a moral attitude and response of will to the character of God as He has been revealed in Christ. It is like the act which closes the electric circuit, which act at once releases power. The dynamic effect which follows the act is the best possible verification of the rationality of the act. So, too, faith as a moral response is no blind leap, no wild venture; it is an act which can be tested and verified by moral and spiritual effects, which are as real as the heat, light, and horse power of the dynamo. Faith has come to be recognized as an energy in many spheres of life. We know what a stabilizer it is in the sphere of finance. Stocks and bonds and banks shift their values as faith in them rises or falls. _Morale_ is only another name for faith. Our human relationships, our social structures, our enjoyment of one another, our satisfaction in books and in lectures rest upon faith and when that energy fails, collapses of the most serious sort follow. We might as well try to build a world without cohesion as to maintain society without the energy of faith. We have many illustrations of the important part which faith plays in the sphere of physical health. The corpuscles of the blood and the molecules of the body are altered by it. The tension of the arteries and the efficiency of the digestive tract are affected by it. Nerves are in close sympathetic _rapport_ with faith. It is never safe to tell a strong man that he is pale and that he looks ill. If two or three persons in succession give him a pessimistic account of his appearance, he will soon begin to have the condition which has been imagined. Dr. William McDougall gives the case of a boy who was being chased by a furious animal and under the impulse of the emergency he leaped a fence which he could never afterwards jump, even after long athletic training. The list of similar instances is a very long one. Every reader knows a case as impressive as the one I have given. The varieties of “shell-shock” have furnished volumes of illustrations of the energy of faith, its dynamic influence upon health and life and efficiency.