"Why" is the question. To answer, that we must look deeper. We must look within ourselves and even deeper. We must look at the very nature of this Universe. There we can find the reason we are driven to desire Unity and pursue it even by harmful means.
Modern science tells us that our Universe was created by a "Big Bang". This theory states that all matter and energy that is now dispersed throughout this Universe originated from a single, ultra dense point. Some catalyst caused this singular point to explode and our Universe was born. This theory is widely accepted and backed up by the fact that currently our Universe is still expanding from this initial explosion.
As below, so above. This principle tells us that everything is similar both upwards and downwards. Modern science affirms this. All things are a part of larger systems and are built of smaller systems. Atoms make molecules make compounds make cells/structures make organs make organisms, make ecosystems make the Earth what it is. It goes higher still. The Earth is a part of our Solar System. The Solar System is a part of a Star System. It can be expanded and contracted in both directions indefinitely. This is hard science that most anyone can test. This information is of no surprise to anyone. As below, so above.
That principle holds true for more than just system structures. It also holds true for energy structure and waves. It holds true for cycles as well. All things follow a Life/Death cycle. A seed sprouts a root. The root grows a tree. The tree matures. The tree drops a seed. The seed sprouts a root. Cells of your body are multiplying and dying right now. The old making room for and creating the new. The Life/Death cycle is inescapable. Expanding and contracting forever in all aspects and in all directions. "As below so above and beyond I imagine."
From this information one can safely assume that the Universe is no different. From one single point to an expanded Universe back to one single point. Once the Universe is completely expanded it will once again converge on itself until it is all a singular point again. Would Consciousness not follow this same model? All Consciousness originated and emanates from a singular point and it is destined to return to that point. This is the truth of the Life/Death cycle.
What's this have to do with our innate desire to pursue Unity? Well, our consciousness is aware of its origin. It's aware of our Oneness and of our connectedness. Even those ignorant to this fact subconsciously know it and desire it. We have all felt it and sought after it. Some use religion. Some use drugs. Some use power and greed. For those of us that have felt and acknowledged this Unity it isn't hard to accept this. We have felt the Oneness. We don't need to speculate about its existence.
This explains the attempts of Man to unify or conquer all humanity throughout history. It explains the current rise of socialism and the New World Order. We desire to be unified. We WANT to feel our Oneness. However, this Oneness cannot be achieved forcefully. It won't and hasn't worked. This Oneness is not a Oneness of this world but a Spiritual Oneness. No variety of government, dictator, or religious institution can provide this Oneness. Only True Desire, True Will can. Only through Spiritual means can we fulfill these desires so we must make our very desires Spiritual.
The idea of “As below, so above” is prevalent in hermetic and mystic teachings. The idea that things are the same upwards and downwards . The more science probes, the farther out we look and the farther in we look we continuously find that this idea is very real and very true. It is not unreasonable to believe that things go on forever in all directions. Things are always going through endless Life/Death cycles in every imaginable way. It applies to all things both material and immaterial. With this in mind understanding the Nature of the Universe becomes a little easier. For me at least. That idea hit me years ago. The more I learn the more defined that idea become. As humans, we could never imagine the beginnings or endings of any of this. We can never zoom in enough or look out far enough to find the end. Our lifespan and understanding of time severely cripple us from being able to understand. However, I think that once you accept that things do go on forever and infinitely then you can start to understand it all better. That’s the key. Understanding the very Nature of the Universe is paramount. That’s why I love tools like DMT. It allows you to play with the fabric of the Universe. Examine the properties of it. Stretch it and compress it.
“Do not make the mistake of supposing that the little world you see around you - the Earth, which is a mere grain of dust in the Universe - is the Universe itself. There are millions upon millions of such worlds, and greater. And there are millions of millions of such Universes in existence within the Infinite Mind of THE ALL”
― Three Initiates, Kybalion