The mind or will is the master of the body. The condition of the mind is largely affected by the condition of the body. A sound mind in a sound body is the ideal condition. To keep the body and the mind in proper condition, it is essential that they be exercised, for it is a law of nature that inaction produces decay and disease. Any stagnant pond is a good illustration of this law. The Christian, whose desire is to serve his God and his fellow-man, and who wills to do so, should recognize that he can work out his will and desires more effectively with a sound mind and a sound body than with those that are disabled or injured through neglect or disuse. Considering the body from this standpoint, as an instrument or a machine to be utilized by the will in accomplishing good works, it would be the part of wisdom to have it in excellent condition in order to achieve the best results. The orderly, systematic care of the body tends to develop those very traits of character that are essential to the Christian development. Temperance, self-control, determination, patience, self-denial, etc., are naturally acquired by those who pursue a regular course of training with the object of devoting their time and energies to the service of their Lord. The Apostle says, "Bodily training is profitable for a little; but piety is profitable for all things, having a promise of the present life, and of that which is future." (`1 Tim. 4:8`)