A very good question, one that has been asked many times before and no one has ever come up with an answer. Another way of putting it: "Do mathematicians invent mathematics, or do they discover it?"

The way I like to think of it, the universe is, it has a reality and it is perceivable through our senses and through devices which assist our senses. We are even capable of affecting it, to a limited degree. We have evidence that there are other minds than ours, and that we can compare observations and conclusions with them through language, although this process does seem to have many pitfalls and shortcomings. The non-human phenomena which we perceive around us (like gravity or fire) can be described with language and mathematics, and although the former is applicable to many situations, it really gives us very little in the way of precision or completeness. Mathematics is only applicable to certain limited types of phenomena, but it is extremely precise, and allows us to make predictions and statements which we simply could not make with language alone.

Language appears to be the way we communicate with others, while mathematics seems to be the only way we have of getting straight answers about the rest of reality. In fact, it appears to be the only way we have of asking meaningful questions on those parts of the universe which are not conscious entities like ourselves.

I personally do not believe in a purpose to anything, the universe just happens and we are a part of it. It is not here for our amusement or enlightenment, although there is certainly no reason why we can't enjoy and appreciate it while we're here. Every human life is a minute interruption of the oblivion that precedes and follows it, like a rain drop entering the sea, but I do not find this depressing. On the contrary, what a wonderful gift that for even a brief moment we can look around and watch the show, play the game. The world doesn't have to be created for our benefit, we're just lucky to know it, however briefly, and to ask anything more of it seems to me to be insufferably arrogant and conceited on our part.

Listen carefully, I'm going to tell you a very big secret about myself...
I may be wrong, because I certainly can't prove this, but I am absolutely, completely, unequivocally convinced that the universe, (or god, or the great spirit, or cosmic consciousness, or whatever you call it) has absolutely no idea that I am here. I am aware of my surroundings, but they are not of me, even though I interact continuously with them. The only intelligence aware of my intelligence is that of those people around me that know me, and that includes you. The only cosmic consciousness is that which we share as sentient beings. We ARE god. Everything else is just matter and energy interacting in time and space, held together by a few simple mathematical rules to keep the bookeeping straight.