It is very likely that we are all "One" in the sense that we are all made from the same materials as the Earth. The Earth is a collection of asteroids that collided with each other, and perhaps the same is true of other planets in the universe. Even beyond these asteroids, there is a specific, universal energy called "Zero-Point Energy." This energy was not necessarily created by a deity, but simply fluctuates in and out of existence, thus creating the universe.
I find this theory to be very interesting, but I am no expert. Additional reading is required for anyone interested in this concept. However, even if we are unique as individuals in our personalities, interests, and so on, it is reasonable to claim that we all have an origin. This origin may be one or more gods, or a universal, fluctuating energy.
In one way or another, none of us are actually made from a unique set of materials. We all consume the same materials by breathing, eating, drinking, and even before -- by being combined into a single entity by sexual relations.
-- An assessment I wrote to a reader.
According to the ideology of individualism, every individual being is unique, meaning that they are different enough from any other being to be considered distinct. However, there is a problem with this premise. If we can find even one person who is bland enough to be considered not unique, then perhaps we are not as special as we think we are.
I hold this ideology dear to my heart, but I also believe that it is important to be realistic. We are all unique in our own way, but we are also all human beings with the same basic needs and desires. We all make mistakes, and we all have the potential to do great things.
I believe that it is important to celebrate our individuality, but we should also remember that we are all connected. We are all part of the same human family, and we all have a responsibility to each other.
It is possible to blame the process of socialization for this conclusion. After all, socialization is designed to make individuals conform to the norms, and the more normal you are, the less unique you are. This could be a reason why individualism is rightfully seen by some as false.
This led me to form my own kind of individualist ideology, which believes that individuality is to be earned, and is not inherent to one's existence simply because we are separate beings. Without the work of finding and/or creating your distinct individuality, that individuality will either stay hidden or non-existent.
In addition to this contemplation, we can also claim that individuality is not so dominant in its presence due to the fact that we are all "made" of the same materials; materials that can be found in food, fluids, and theoretically on soil (those who are buried without a coffin technically become a part of the Earth). Furthermore, the materials that Earth is composed of are also contained, whether completely or partially, on other planets, regardless of how far they are from us. If we are all made from the same set or sets of materials, what is so special about us materialistically, if one's particles are not so distinct than another's, other than the fact that they are in a different being and/or are differently embedded within the body?
Because of this reasoning, there is no need to "retreat" to the spiritual realm in order to argue for the universality of existence, as that universality could be correct no matter how religious or irreligious one is in their beliefs. In a sense, we are all one, but in separate bodies and constructs. It doesn't matter if you believe in one or more gods, evolution, or whatever -- even in the separation of being, there is a common origin, a common resource. We all need materials that exist in our environment in order to sustain ourselves -- oxygen, protein, H2O, and so on -- even if said materials don't exist on many planets, they do exist on planets that are similar to our own home world.
What is, therefore, so unique about water from outer space to water from this world when they have been, essentially, constructed by the same particles, which we ourselves are composed of? After all, we are mostly water. If we were to drink said water from another planet, assuming that water is as drinkable as here on Earth, will we become different in our personalities, or in our bodily composition? Unless there is a special agent in that water, we will logically stay the same, as the water in that region of the universe is as drinkable and life-sustaining as it is here. Otherwise, we would suffer from illnesses or even death; that would mean that water wasn't as drinkable after all.
Regardless of the "outer space water" argument -- whether you believe in an Abrahamic religion or in the validity of science -- Earth and all of its existence had to be formed in something external of it, as it couldn't just have popped out of existence. Since there were already things outside of it (asteroids, other planets, and so on), it would be inevitable to conclude that Earth was formed out of things that were already present.
And indeed there is some truth in the Old Testament, when it argues that in the very beginning there was chaos. What was that chaos? It was but the chaos of anything that collided into each other and thus formed the Earth as it was many millions of years ago (further reading). Unless we came from an external origin, like extra-terrestrial beings (assuming it could be true, of course), our common origin as biological beings are pretty much the many particles that were drawn into the Earth and thus formed it.
Are we all that unique?
Physically, the vast majority of us are not. We are all composed of very similar particles, and we consume these particles in order to sustain ourselves. It is logical, to an extent, to see who we are based on our nutrition.
The only way to achieve true individuality is to develop our own character to the point where it is unique enough to be distinguished from others. We cannot hide from the fact that we are human, or that we have a common ancestry with many people. We cannot escape from Earth to be the first colonizer of another planet (yet). However, we can work on becoming more unique, so that we can be distinguished from others.
In a sense, we are all "one" that has been multiplied into countless bodies and entities, like rain from a cloud. If we assume that "Zero-Point Energy" is true, then we are all formed from a universal stream of energy that is present everywhere. Therefore, there is no need to retreat to more spiritual/mystical/occult theories of oneness. The physicality of our existence seems to do the job just as well.