Given a fixed point and you can move the world. In many ways, your language provides you with the tools to wrap your mind around the world, express its essence in a way that may be understood by the people you communicate with and help you to shape the world as you know it.
Language is both individual and shared. My English has been shaped by my schooling in the Netherlands, my stay in the United Kingdom and the many times I expressed myself in e-mail, articles, presentations and when skyping. Typically I get it right but a text can be understood by some and misunderstood by others. It is my English but to function it has to be expressed in a way that is shared with others.
For some subjects I prefer my native language, for others I prefer English. To communicate, the language used must be sufficiently shared by everyone involved. The language must be received; when I am surrounded by a vacuum, nobody will hear me talk. To read this blog, you either have access to a computer or someone must print it out for you.
A language lives when people use it, when it is part of a distinct community, a distinct culture. When the boundaries around such a community or culture disappear 0r change, the language either morphs or it dies. To understand history, you have to understand its artefacts and its language. Many languages die and died and with it we lose the history, the culture of the people that spoke that language. They may leave their literature, inscriptions and when enough is left, we may understand what is says. The trick will be to understand it as it was meant when the language, the culture was alive.