the bravery of atheism

I have been thinking alot lately about the reasons for atheism (stimulated by reading Brian McLaren's book Finding Faith) and it is such a huge issue that I am not going to get into the whole argument because it is so large and complicated and I am just not theologically articulate enough to attempt it. My only real thought is that you have to be very brave to be an atheist, braver than you do to be a person of faith. To believe that there is nothing at all outside of us and that this life is all we have to live for almost takes a bigger leap of faith than believing in the existence of God. One of my closest friends is an atheist and we have had some lengthy discussions about this. I have asked him repeatedly what he believes and he says science makes it rationally impossible to explain the existence of God therefore He cannot exist. I told him that leaves some VERY big questions unanswered about the universe and makes science a religion in itself. It is an ongoing dialogue between the 2 of us and will probably continue to be for awhile.