It's an open question without a correct answer. That's not because no one knows what the answer is but because there is no answer to be known. So believe or think what you will and do what you find worthwhile.
Even if there were some facts about the genesis of the universe, such that it was created by a "higher" being that had purposes for everything in it, those purposes still wouldn't by themselves be a 'correct' answer to the question. You can find a meaning or purpose different from your originally intended function and not be somehow inaccurate. I maintain that there is no originally intended function, but even if there were it doesn't ultimately matter. Life is just what you make of it.