Unity in the force
Everything that exists exists within The Force. There is nothing outside of The Force, for The Force makes up all things that are. This idea is one that must be understood thoroughly, because to understand the Sith ideology, we must understand what The Force truly is. We know that The Force is the energy that makes up the universe, but this has larger implications that we must examine. What it truly means is that we are The Force, and The Force is us. The experience of separation of any kind is an illusion created by our forced perspective. Our physical forms do not possess the ability to see the manner in which we are one, however, we can demonstrate it through science, with the powerful tools that we have developed to understand the universe. There truly is no "out there" and "in here". Our physical bodies are simply unable to experience our unity with The Force through our physical senses. Still, it is very much the case. This means that I am you, and you are me. We are all one. We are all The Force; not just a part of The Force, but The Force in its entirety. Yet, because of our limited perception, we are all individual simultaneously. This is the nature of The Force, as this is the nature of the universe.
One of the most powerful ways that we can come to better understand and know The Force is through our relationships with other people. When we come to know others, when we form deep connections with other people, we are coming to know The Force, and hence, we are coming to know ourselves as well. This is one of the highest forms of self discovery. In fact, it is more accurate to say that relationships are not something that are made, but rather, relationships are something that are discovered. We are discovering a part of our connection to another person that already exists in our unity in The Force. We are, in part, discovering our true nature, and therefor, the true nature of the universe, and the true nature of The Force. The more fully we can understand this, and the more fully we can understand one another, the more fully we will understand the Sith ideology. This is one of the reasons that altruism and ethical behavior are so important; the manner in which we treat others is really the manner in which we treat ourselves. To harm another is to harm ourselves. To love another is to love ourselves. To bring joy to another is to bring joy to ourselves.
When we come to realize our unity in The Force, we come to understand something else as well. Because we have sentience and the ability to make decisions, we are in part directing the development of the entire universe through our will. Our every action ripples through all of existence, in a complex series of cause and effect. Chaos theory tells us much about the truth of this. We may not be able to see the repercussions of our actions, but that does not mean that there are none, or that those repercussions are small or unimportant. Each of us is helping to direct and guide the development of the greater self that is The Force. This is something that we must take responsibility for, and something that we must take seriously. This is the importance of self ownership. What impact do we wish to have on the universe? Once we know the answer to that question, we can begin to work towards accomplishing it.