The fourth thing concerns people’s eyes: light. This too is very important. When you see a bright light, and its brightness reaches a certain strength, it is capable of blinding human eyes. After all, human eyes are eyes of the flesh. They cannot bear irritation. Does anyone dare to stare directly into the sun? Some people have tried it, and if they are wearing sunglasses, it works just fine—but that requires the use of a tool. Without tools, man’s naked eyes have no ability to face the sun and stare directly at it. However, God created the sun to bring light to mankind, and this light, too, is something He took care of. God did not simply finish creating the sun, put it somewhere, and then ignore it; that is not how God does things. He is very careful in His actions, and thoroughly thinks them through. God created eyes for mankind so that they may see, and He also set in advance the parameters of light with which man sees things. It would be no good if the light were too dim. When it is so dark that people cannot see their fingers in front of them, then their eyes have lost their function and serve no use. But light that is too bright renders human eyes equally unable to see things, because the brightness is intolerable. Therefore, God has furnished the environment of mankind’s existence with an appropriate amount of light for human eyes—an amount that will not hurt or damage people’s eyes, let alone cause them to lose their function. This is why God added layers of clouds around the sun and the earth, and why the density of the air is able to properly filter out types of light that can hurt people’s eyes or skin—these are commensurate. In addition, the colors of the earth that God created reflect sunlight and all other kinds of light, and are able to eliminate the sorts of light that are too bright for human eyes to adapt to. Thus, people are able to walk outside and lead their lives without needing constantly to wear very dark sunglasses. Under normal circumstances, human eyes can see things within their field of vision without being bothered by the light. That is to say, it would be no good if the light were too piercing, nor if it were too dim. If it were too dim, people’s eyes would be damaged, and, after brief use, ruined; if it were too bright, people’s eyes would be unable to withstand it. This very light that people have must be suitable for human eyes to see, and God has, through various methods, minimized the damage caused to human eyes by light; and though this light may benefit or afflict human eyes, it suffices to let people reach the end of their lives while maintaining use of their eyes. Was God not thorough in considering this? Yet the devil, Satan, acts without such considerations ever passing through its mind. With Satan, the light is always either too bright or too dim. This is how Satan acts.

God did these things to all aspects of the human body—to its vision, hearing, taste, breathing, feelings, and so on—in order to maximize mankind’s survival adaptability, so they can live normally and continue to do so. In other words, the current environment for life, created by God, is the environment most suitable and beneficial for the survival of mankind. Some people may think that this does not matter a great deal, that it is all a very ordinary thing. Sound, light, and air are things that people feel are their birthright, which they have enjoyed from the moment they were born. But behind these things that you are able to enjoy, God has been at work; this is something humans need to understand, something they need to know. No matter if you feel there is no need to understand these things or to know them, in short, when God created them, He gave much thought to them, He had a plan, He had certain ideas. He did not frivolously or simply put mankind into such an environment for life, without giving the matter a second thought. You may think I have spoken too grandly about each of these small things, but in My view, each thing that God provided for mankind is necessary for the survival of humanity. There is God’s action in this.

—The Word, Vol. 2. On Knowing God. God Himself, the Unique VIII