God's stamp is upon us. He has bought us, and He desires us to remember that our physical, mental, and moral powers belong to Him. Time and influence reason, affection, and conscience, all are God's, and are to be used only in harmony with His will. They are not to be used in accordance with the direction of the world; for the world is under a leader who is at enmity with God.
The flesh, in which the soul tabernacles, belongs to God. Every sinew, every muscle, is His. In no case are we by neglect or abuse to weaken a single organ. We are to co-operate with God by keeping the body in the very best possible condition of health, that it may be a temple where the Holy Ghost may abide, molding, according to the will of God, every physical and spiritual power.
The mind must be stored with pure principles. Truth must be graven on the tablets of the soul. The memory must be filled with the precious truths of the Word. Then, like beautiful gems, these truths will flash out in the life.
Source: Bible Universe