Tucked into the middle of Psalm 36 is this article’s title, which is arguably one of the most profound phrases in all of Scripture. Expressed as a sort of paradox, this phrase conveys a wealth of truth about God, His Word, and our Lord Jesus Christ.1 To grasp its richness, it will be helpful to understand a few things about the nature of light as a creation of God and then to see how light is used as a metaphor for deep theological meaning throughout Scripture.

My intentions for the next few articles in this rubric are to explain a bit about the science of light, and then to explore the storehouse of passages in Scripture that either use this word or refer to a related concept. From this study, we will see that light is one of the most typologically rich words in the Bible, suiting its status as the first of God’s creatures. With both the science and the theology in mind, we will return to the paradoxical character of our title—and of light itself—to understand the meaning of the psalmist in Psalm 36:9.

The science of light

The material creation is composed of two fundamental components: energy and matter. Although there are many different properties that characterize each of these fundamental components, the simplest distinction between them is that matter has mass whereas energy does not. This distinction helps us to distinguish between physical elements like gold and silver, which can be measured on a scale, and “pure” energy like light, which has no mass and therefore cannot be weighed on a scale.

It is interesting to note that both energy and matter appear immediately in the Genesis 1 account of the first day of creation. Though light is the primary focus of God’s creative act on the first day, reference is also made to the Spirit moving upon the “face of the waters,” which implies the presence of the elements—the matter—that compose water. Precisely what variety and complexity of matter was created along with light on the first day is a mystery, but it is clear that in the very beginning God created energy and matter. From these two basic building blocks He formed the rest of creation in the following five days.

Because matter has physical properties that we can identify with our senses, it is probably the more intuitively grasped of the two fundamental components of the creation. All matter is made up of atoms, which in turn are composed of the same basic particles: protons, neutrons, and electrons. Like all matter, these particles have measurable mass (though it’s very small!) that remains constant. Although these basic particles can be arranged into many different atomic elements (118 have been discovered thus far!), which can themselves be combined to make a truly endless variety of molecules, matter is “simple” in terms of its physical makeup.

Energy, on the hand, is a much more variable category because there is no single set of basic building blocks or simpler components that can be invoked as a unifying principle. Though different types of energy may have overlapping properties, they remain distinct in terms of what they do and how they are detected. Consider, for example, the forms of energy we call light and sound. Light energy is detected by the photoreceptors in our eyes and allows us to see the creation around us in all its beauty and complexity. Sound energy is detected by the small hair cells in our ears and allows us to hear what is going on in the creation around us. Though distinct from one another, both light and sound energy are produced as waves, which means they occur at different frequencies and amplitudes that create variety in what we see or hear. The difference between red light and blue light is in their distinct wavelengths, which is similar in concept to high-pitched sounds and low-pitched sounds that also differ in wavelength. So, while there are similar concepts and properties that can be used to distinguish the different forms of energy, defining the category as a whole is difficult.

The simplest definition that encompasses all forms of energy is “the capacity to do work.” This is somewhat of an abstract definition, so an illustration of what this means is helpful.

The easiest way to think about “doing work” is by moving something heavy. Anyone who has moved a heavy box of books from the basement up to the main floor of his or her house knows intuitively that it takes energy to make that trip up the stairs. The heavier the box and the faster that one moves it up the stairs, the more energy that is required to do the work of moving it. In mathematical terms, we would say that the energy required to do this work is the product of mass times acceleration, which gives scientists and engineers a handy way to measure how much energy is required to do any given sort of “work,” from moving individual molecules to huge steel beams required to build a highway overpass.

How physical measurements of the energy required to move objects relates to light is perhaps not obvious at first glance, since we do not usually think about using light to do the work of moving things around on the scale of everyday life. Shining a flashlight on your couch, for instance, does not make it move across your living room! But if enough light energy could be stored in another form, it might be possible to convert that stored energy into something that could move your couch around your house. To understand how this is possible, we need to delve briefly into both the physics and chemistry of light.

Much of the discipline of physics is focused on how different forms of energy relate to one another and how one form can be converted into another. Physicists typically define six fundamental kinds of energy, each of which can be broken down into a multitude of different categories. Light energy is a form of radiant (or electromagnetic) energy, a category that also includes infrared energy, microwaves, and radio waves. All forms of radiant energy are produced as waves that can be detected with devices that are tuned to their specific wavelength, most of which are invisible to the human eye. Radiant energy readily interacts with matter and can be absorbed (or emitted) by materials with a physical composition that corresponds to the specific wavelength of energy being studied. The process is complex but occurs all around us every moment of the day whether we realize it or not.

This is where chemistry becomes important, because the study of molecules helps us to understand how the energy in light can be converted into something that is more obviously physical in nature. Chemical reactions are essentially exchanges of energy from one form to another. The bonds that connect the individual atoms of a molecule together are something like miniaturized batteries that store different amounts of energy depending on the atoms involved. A chemical reaction involves the rearrangement of these bonds such that energy is either absorbed or released into the surrounding environment.

Perhaps the best example of chemical reaction that releases energy is a combustion reaction in which some material is burned. A wax candle is a good example. When a spark is used to ignite the wick of a candle, it begins to burn in an ongoing chemical reaction between oxygen from the surrounding air and the hydrocarbon- rich wax of the candle. This combustion reaction converts the wax and oxygen into carbon dioxide (CO2) and water (H2O) while also releasing light and heat— both forms of pure radiant energy.

Now take this concept one step further as we consider how work is being done by light through its conversion into mechanical motion through chemical intermediates. Light from the sun shines on the earth and is absorbed by plants. Through the marvelous process of photosynthesis (which is essentially like running combustion in reverse), this light energy is converted into chemical energy through the production of sugars that can be stored in the roots, seeds, or fruits of a plant. When a person consumes and digests a piece of fruit or bread made from seeds of grain, the sugars in that food undergo another chemical reaction that allows muscle cells to contract, which in turn allows arms and legs to move about. Through this conversion of chemical energy into mechanical energy, a person can move a couch across the living room—thus “doing work.” All this work was made possible by the sunlight that was used to drive the chemistry of photosynthesis; so in effect, the energy of light was indirectly used to “do work.”

The sorts of energy transformations described in the examples above are what make life on earth possible. Without a continuous source of light energy from the sun and the presence of key chemicals like water and oxygen, it would not be possible to sustain biological life on earth, or anywhere else for that matter. The life-giving power of the sun, which has been recognized by people in every era since the beginning of time, is an absolute necessity for our existence. All of God’s living creatures—even those living in the darkest caves and underground environments on earth—depend either directly or indirectly on sunlight for their survival. It is no wonder, then, that the first of God’s creatures is such a common and powerful metaphor in His Word!

In our next article, we will turn to the theology of light and consider the many different ways that this word is used as a metaphor in Scripture. As a prelude to this transition, we end this article with a fine quotation that points our hearts and minds to the greatness of our Creator, the Lord of light.

In short, our pastor noted that Calvin, with Augustine, would think of God as one thinks of the sun. All other lights in this world are derived from the sun. One does not first think of other lights as though they shone in their own power, in order after that to investigate openmindedly whether the sun exists. So one cannot first think of the facts of the universe, and especially of the mind of man, as though they were possibly not Goddependent but self-sufficient as so many self-powered light bulbs, in order then to inquire whether God exists. One just does not look at light bulbs to find the sun. Knowledge of the sun must precede, and be the foundation of, light bulbs. So one does not look at creation to find a Creator, but rather the latter is the foundation of the former. Therefore true knowledge of creation demands a true knowledge of the Creator.

All the facts of the universe are of necessity Godcreated, God-dependent facts. Therefore men ought to see that God is man’s Creator and his Judge. “For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse” (Rom 1:20).2


1 A paradox is something that at first glance seems to be contradictory,
but when understood correctly expresses a well founded truth.
2 Cornelius Van Til, The Reformed Pastor and Modern Thought
(Phillipsburg: Presbyterian and Reformed Publishing Co, 1980), 9.