We see this universe and we are within this universe as a part of this universe. We see it and we are a part of that. We can say this universe is existing.
Innumerable are the manifestations in this universe but all are existing. I am here. You are there. He is. She is. That is. Right from atomic particles to the grossest universe I am saying these are existing. Many forms of manifestations are there. The immovable things and moving beings are all existing.
When we go behind the knowledge of different properties of these manifestations it will have no end and no limit. But what is giving existence to all these? By which all these are existing? Think about that.
That existence absolute is one and the same. It is without a second. It is non-dual. And that existence absolute is manifesting in different forms with different names in different places. But this existence is one without a second: the non-dual existence. Try to analyse this.
Take a piece of material in front of us. It can be a piece of wood or a piece of iron or steel or glass or plastic. Whatever it is. If there is a book in front of you it is paper and I am saying in front of me is a mobile phone and we say it is there. The book is here or the mobile phone is here. Whatever it is, there is a material thing and we analyse what it is. When we accept the things around us then they are different. A book is different from a mobile phone and entirely different from a steel rod. Whatever it is but analyse it. Try to understand what it is.
Then we will come to certain reacting elements. It is a mix of iron and carbon or it is a mix of hydrogen, carbon and oxygen. So there are different permutations and combinations of some materials; a few materials, say for example, some elements, which may count thirty of forty in number. Their combination and permutation makes the whole difference. Now the innumerable things we observed in this universe became some thirty or forty actively participating or reacting elements. Now I am analysing still further. I am going still deeper.
Then I am seeing these differences in materials only up to their atomic level. There is the atom of carbon that is different from the atom of hydrogen and the atom of oxygen. It is true there are differences. But when I analyse still further I see the same particles in different configurations make different entities. So now the difference has gone.
Now I am observing any nucleus and some electrons which are revolving round and this incessant movement of such particles make an atom. And again I am going still deeper with that analysis.
Then I will find out the constant movement or constant vibrations of the same energy particles make this material. So now there are no innumerable particles. There are no thirty or forty elements or atoms. There are no different nucleus or electrons. But now I am seeing vibrations of the same energy particle. Now where is the material? It has vanished. It is not there. There is no material. Only vibrations of the energy particles.
And to have that there must be a substratum on which these vibrations are happening. So when I analyse this material universe itself, I am reaching at the very base of that as the existence. So there is no difference. All the differences have vanished. Gone forever. Now there is existence alone. And because of that existence all the multitudes, which I am experiencing in this universe, exist.
– Excerpt from Mundaka Upanishad by Swami Chidananda Puri
Swami Chidananda Puri 