I don't think that science should leave questions to religions to answer. My position is that there are certan kinds of questions, like 'why are we here', that science is not in the business of answering. Too, that religions do hand you answers to some of those question. That is all.
My position is that science does a fine job of explaining why we are here. Our own personal existence is explained quite well by biological reproduction. As Modulous mentions above, evolution does a great job of explaining why our species exists.
I have explained in previous posts my position on religions inventing purposes and intentions as it relates to nature. Perhaps a bridge hand will better illustrate what I am talking about (bridge is similar to spades or hearts if you are familiar with those card games). After you have been dealt a hand you could ask yourself why you were given those specific cards. But why would you? You could have received any one of millions of possible 13 card hands, each of them with an equal probability. You have the hand you have because that is the hand you got. It is that simple. There is no divine purpose or evil intention in the cards you received. It is simply one outcome of millions.
I think this does a good job of explaining nature, and by extension us. We are but one result out of trillions of possible results. Given the march of time, one outcome had to occur just as it was inevitable that you would have a 13 card bridge hand. Science does an excellent job of explaining why we are a possible outcome of that process, and in explaining the historical events that led to that outcome.
As to my larger worldview, I see a universe that is indifferent to our existence. The universe cares about our existence to the same extent that we care about the plight of a single bacterium stuck to the underside of a rock in the middle of nowhere. The purpose that does exist in our lives is the purpose we give it. Purpose is not an external or intrinsic property of the universe. Instead, it is nothing more than our hopes and dreams of how the universe should be.