Dharmas are neither produced nor extinguished.
If you are aware of this, then all Buddhas are constantly before you.

This is a quote from the Avatamsaka Sutra. It is the very marrow of buddhism, sums up all of the Teachings of the Buddha, and is the very basis of Buddhism. If you should ask what it was that the Buddha became enlightened about, this is the answer. All the other Teachings of the Buddha are detailed explanations based around this one.
Most people think, however, that everything is mortal, that everything which is born must die. In fact, Buddhism teaches you that there is a continual cycle of birth, aging, suffering, and death. And if this is so, how could the Buddha say that all dharmas are neither produced nor extinguished? What is not mortal? We are surrounded by life that must die; so we wonder why the Buddha said this, and what he meant by it.
If you come to understand this one truth that all dharmas are neither produced nor extinguished, you will found the way, and there is nothing more to know. But it is coming to understand this truth that is so difficult, so everyone doubts the validity of the statement.
If it is true that all dharmas are neither produced nor extinguished, then what is the universe like? It’s the constantly abiding, the eternal. And this universe which is neither produced nor extinguished is called in Buddhism "the eternal Dharma realm," "the constantly abiding realm."
Let me quote the Lotus Sutra for you:

Since Dharma is always in its place,
the mundane world is also constantly abiding.

"Dharma" here is referring to this law of non-producing, non-extinguishing. The heavens of the Devas and the realms of the earthlings are all part of this non-producing, non-extinguishing. Everything is constantly abiding.
Everything appears to the eye to be in a process of birth and death, but that is not the actual case. It is a superficial observation. Actually, the entire universe is constantly abiding and indestructible. In Buddhism we call this Dharmakaya, the ultimate, the reality underlying all things. In the Avatamsaka Sutra, this is also referred to as unlimited causation, the unlimited influence of every thing on all things and all things on every thing. Everything is endlessly intertwined. And that is what is neither produced nor extinguished. Everything is harmoniously integrated in the universe. Regardless of the sometimes kaleidoscopic changes we see, everything is constantly abiding and eternal.
So by realizing this, you come to understand Buddhisrn and all your problems concerning Buddhism are solved. But if you don’t come to this realization, then you’ll never understand what Buddhism is all about.
People then naturally raise another question. If everyone is to make this realization, doesn’t that mean that everyone should go to a temple in the mountains, meditate and follow the path in the traditionally prescribed manner? That, of course, is highly unlikely. For those who cannot clearly understand this truth, however, let’s turn to modern science for a moment for an explanation. After all, isn’t this the age of science? But what does science have to do with "non-producing, non-extinguishing"?
There are innumerable philosophies and religions in this world of ours. But no other system has dealt with this non-producing, non-extinguishing issue so clearly and firmly as Buddhism. I guess you’d have to say that the historical Buddha has the copyright on this one! But science, evidently, has been trying to claim the copyright in recent decades.
How so? Through experiments, atomic physics has proved that nature is "non-producing, non-extinguishing." Albert Einstein was the first to bring this to light in his Special Theory of Relativity.
Nature has two forms as perceived in traditional physics-energy and mass. In Einstein’s special theory, however, he stated that energy is mass and that mass is a form of energy. It was also explained that energy conserves itself; that is to say, energy never loses any of itself, it never decreases. And mass was thought to have remained unchanged as well in the sense that none of it ever got lost. Nowadays, however, energy and mass are no longer considered separate, and consequently they are both included in this same law of conservation.
Exploration of mass led to the discovery of molecules and subatomic particles; and energy is formless motion. But how could mass, a form, be interchangeable with something formless? Such a thing was inconceivable. So at the time of Einstein’s discovery, everyone thought that he was out of his mind.
Einstein certainly started lots of people thinking, and some people working. In the decades to follow, Einstein’s special theory has been proved innumerable times. Mass is a form of energy, energy is mass, and they are mutually convertible. And the first applications were, unfortunately, the atomic and hydrogen bombs.
Converting mass is called nuclear fission, and a tremendous amount of energy is released by this fission of atoms― that’s what we get with the atomic bombs. We can get similar results with nuclear fusion; by combining hydrogen and helium, we get hydrogen bombs. So through science, man has proved that energy and mass are mutually convertible, but man have proved it in a very disastrous manner. C. D. Anderson was the first physicist to succeed with these experiments of conversion, but his successes were not extensive. Then there was Emilio Segre of Italy who fled from Mussolini to the U.S. He was highly successful in a broad range of experiments of converting energy to mass and mass to energy.
Let’s make an easy analogy, one of water and ice. If water freezes, it becomes ice, but the water is not gone. In the same way, if the ice melts, is the ice gone? No. It has only converted itself into water. Water appears as ice, and ice appears as water. The water is ice, and the ice is water.
It`s the same with energy and mass. Energy appears as mass, and mass appears as energy-- they are one and the same. This came to light first in the Special Theory of Relativity, but it also applies to quantum theory which eventually followed the efforts of Einstein.
What happens during such conversion? We think that when water becomes ice, the water is gone and ice has been produced. But actually the water is not gone; it has just transformed itself (non-extinguishing). And ice has not really been produced (non-producing) ; water has only changed form, converting into something else. This is a good example of non-producing, non-extinguishing.
It’s the same with energy and mass. They mutually convert, but there is not even the slightest increase or decrease in volume; and here we have the Buddhist "non-increasing, non-decreasing," which is actually another way of saying "non-producing, non-extinguishing."
Japanese physicists, well aware of traditional Buddhist thought and such teachings as "non-producing, non-extinguishing," "non-increasing, non-decreasing," were not surprised by such discoveries in atomic physics and quantum theory. But Western physicists, unfamiliar with Buddhist thought and terminology, thought that they had found something astounding. In fact, they had merely discovered what the Buddha had said so very long ago. The difference is merely in terminology.
The law of conservation specifies that there is no loss of either energy or mass. Again, this verifies the world of non-producing, non-extinguishing, non-increasing, non-decreasing. In Buddhism, this is the eternal Dharma realm. The Special Theory of Relativity makes the point that the universe is eternal, which in Buddhism is the constantly abiding realm, the eternal Dharma realm. Nature is composed of energy and mass which are non-producing, non-extinguishing, non-increasing, non-decreasing.
This is not to say, however, that "non-producing, non-extinguishing" would be a lie or a fantasy if Einstein had not presented his Special Theory of Relativity. With his eyes of wisdom, the Buddha became enlightened to this very fact that the universe is constantly abiding. It is, however, interesting to note that for thousands of years most people were unable to comprehend the meaning of this, and that it has taken science in this century to make it easier to understand for the average person.
Nowadays we hear a lot of people say that Buddhism is too difficult to comprehend, so I have taken the special theory of relativity to make Buddhism’s fundamental teaching a bit clearer for you, and I hope that it is of some help in your understanding.
Many people say that they really don’t know much about Buddhism, and that it seems too lofty, too deep, and too vast for them to comprehend. They think it seems too irrelevant to be compatible with modernity, and that you have about as much chance of understanding it as you do of getting a stroke of lightening to cook you a bean. But it is not all that difficult if you understand its basic foundation of non-producing, non-extinguishing in terms of the examples I have used.
In The Heart Sutra, we have another important phrases:

Form is no different from emptiness,
Emptiness is no different from form.
Form is emptiness, and emptiness is form.

This is another seemingly unsolvable riddle. How can form be emptiness? For example, can emptiness become a rock and can a rock become emptiness? No, of course they can’t become each other. Because they already are each other.
Take a rock as an example. lt is composed of molecular configurations, and the molecules are composed of atoms, which in turn are composed of electrons and neutrons, and particles. It is precisely these subatomic particles, however, which prove that form is emptiness and emptiness is form. In both nature and in experiments, when these particles are destroyed through collision, their masses can be transformed into kinetic energy. Matter is energy, and energy is matter, and they are constantly alternating. A rock is solid form to us, but it is composed, ultimately, of these subatomic particles which are constantly shifting bundles of energy. When they appear, we have form, and when they disappear, we have emptiness. So now you understand why, in Buddhism, we don’t talk about objects; rather, we talk about constantly changing events.
The deeper we investigate, the greater the proof of the validity of the Teachings.
People also speak of four-dimensional space-time continuum, another point brought up by the theory of relativity. Minkowski was first to present a mathematical formula to prove the point. In a lecture on the subject after completing the formula, he said something to the effect that existence transcends time and space, and that time and space could no longer be treated as separate entities. He felt that the age was coming when the two would be perceived as one.
Time and space cannot be considered as separate. If I say, "Today at Haein-sa...," both concepts of "today" in time and "Haein-sa" in space are included. We are right here today, and we couldn`t be anywhere else at the same time. Previously, three-dimensional space was considered separate from time, as we tend to think in daily life. But they are not separate; they are united in a world which is now called the four-dimensional continuum.
So?
In the Avatamsaka Sutra, we have another term, "the all-pervading Dharma realm" in which time and space are completely syncretized. This is what Minkowski was talking about, but he used a mathematical formula to prove the existence of this four-dimensional continuum.
I have covered "non-producing, non-extinguishing," "non-increasing, non-decreasing" and the all-pervading Dharma realm. And these are what we are talking about when we talk of the Buddha’s Middle Way. When the Buddha gave his first sermon at the Deer Park after Enlightenment, among his first words were, "I have found Middle Way." So this is where Buddhism begins.
The Middle Way is the art of syncretizing all contradictions. Usually people think in terms of "good" and "bad." But The Middle Way is transcending these dualities. By transcending dualities, however, what do you have, "not good" and "not evil"? No. You have good and evil which are mutually convertible. Good is evil and evil is good, and they mutually convert. Think of this in terms of the interchange of form and formlessness.
The Middle Way is coming to see that everything is already syncretized, already united as one. Contradictions and dualities are transcended, and everything flows together just as energy and mass flow as one. There is a common misconception, however, that The Middle Way is a middle path between two extremes, which it is not. It is transcending such contradictions as "producing" and "extinguishing." It integrates them so that producing is extinguishing and extinguishing is producing. when energy converts to mass, is energy extinguished and mass produced? No. Extinguishing is producing and producing is extinguishing. The extinguishing of energy is the producing of mass, and the extinguishing of mass is the producing of energy. They are syncretized and they are and one the same.
Let me talk about dualities for a moment in terms of being and non-being. The Middle Way is neither being nor non-being ("not being, not non-being"). It transcends being and non-being. Yet being and non-being exist ("also being, also non-being"). In other words, being and non-being as perceived on the three-dimensional level are syncretized on the four-dimensional continuum where they are mutually convertible. The Buddha said that The Middle Way was this syncretizing of being and non-being. At this level, being is non-being and non-being is being. Go back to "non-producing, non-extinguishing,"-- they are not separate, but rather different forms of each other. The same with being and non-being. On the three-dimensional level, they are seen as dualities; on the four-dimensional continuum, they are syncretized into one and the same. Consequently, everything is unobstructed and free-flowing.
This has always been difficult for people to comprehend, and people thought the meaning was as elusive as a cloud in the sky. But the Special Theory of Relativity has made it much easier to grasp than a drifting cloud. Nowadays, however, there are few who try to grasp this and even fewer who actually do. And some people try to equate The Middle Way with Hegelian dialectical materialism, but dialectical materialism includes the contradiction of a separate time process, whereas in Buddhism all contradictions, dualities and opposites are integrated into one on the four-dimensional continuum.
So being is non-being, and non-being is being; right is wrong, and wrong is right. By applying this Middle Way, all arguments and conflicts, struggles and contradictions disappear. There is not a single reason for quarreling. And that is the state of paradise, of heaven, of the world of the Absolute. So we have, as 1 mentioned earlier from the Lotus Sutra:

Since Dharma is always in its place,
The mundane world is also constantly abiding.

You see, although we perceive the world as being filled with things which are being produced and being extinguished, this is not so in fundamental reality. Fundamental reality is the constantly abiding, the eternal, the state of non-producing and non-extinguishing.
Now you may ask where this principle of non-producing, non-extinguishing came from. It didn’t come from anywhere― the universe is non-producing, non-extinguishing. It is constantly abiding. If you come to understand the perfect oneness of everything through this "non-producing, non-extinguishing," if you come to realize it fully and live accordingly, then you have no need of paradise or heaven. Wherever you are is the world of the Absolute.
Buddhism claims that all forms of life are absolute. If you open the Eyes in the way I have described, then you will come to see that this temporal world is in fact paradise. So you have no need to seek it elsewhere. Just try to open the Eyes. You will see that the sun brightens the entire universe. when you see this fundamental reality, do you need to chant to get to paradise, do you need to believe in Jesus to get to heaven? Wherever you are is paradise, heaven, the world of the Absolute.
The difference is this: if you open the Eyes, you are in the absolute world of non-producing, non-extinguishing; but if the Eyes are closed, you live in the world of producing and extinguishing, the world of life and death, the world of relative dualism, the darkness of the middle of the night.
I hope that today’s discourse will help all of you to open the Eyes completely. Let’s all try our best to accomplish this together.

General Dharma Lecture, January 6, 1981, Haein-sa from Songchol-net(www.songchol.net)