Machinery of Body Must Continue Its Work
Study the Lord’s plan in regard to Adam, who was created pure, holy, and healthy. Adam was given something to do. He was to use the organs God had given him. He could not have been idle. His brain must work, not in a mechanical way, like a mere machine. At all times the machinery of the body continues its work; the heart throbs, doing its regular, appointed task like a steam engine, forcing its crimson current unceasingly to all parts of the body. Action, action, is seen pervading the whole living machine. Each organ must do its appointed work. If physical inaction is continued, there will be less and less activity of the brain.— Letter 103, 1900 1MCP 115.2
