What is the purpose of a god?

there is no use in having a personality behind the universe(no matter its intentions, if it created the universe and we are just a piece of its will then we have no purpose and neither does it ie. if we exist to serve it then what purpose does it serve? why is it there? why does it do anything? why would the universe have use of this being? we exist in a complex web of actions, we exist as a part of the machine as a part of evolution, all we can really do is exist and live life. what use would such a being serve? what would it contribute to furthering the evolution of beings? and on a further note before anyone uses the whole "came from nothing" cop out, the big bang only explains how the universe reached its current state... i mean people claim "so and so god created the universe cant you see that?" all the time, but they dont really think about it it seems like, what purpose would such a deity serve? to create and watch over the universe? then why does it seem that gravity can do the same thing, and as for watching over it it goes back to Epicurean thought on the problem of evil? i mean stop and think about it, there is no evidence for any god creating the universe, why do people cling so tightly to the belief that a deity is necessary for the universe to exist? what purpose would that deity serve by creating the universe? who would keep it in check? and why create it in the first place? with the idea of a personality behind the universe these are questions that would have to be answered...