Beyond the universe there is nothing and within the universe the supernatural does not and cannot exist. Of all deceivers who have plagued mankind, none are so deeply ruinous to human happiness as those impostors who pretend to lead by a light above nature. Science has never killed or persecuted a single person for doubting or denying its teachings, and most of these teachings have been true; but religion has murdered millions for doubting or denying her dogmas, and most of these dogmas have been false.I'd call myself an agnostic rather than an atheist*, but this message rings very true for me.
*In this I follow my father, who answered my question "what religion are you, Dad?" thus: it is not that we do not know whether God exists (which can be resolved one way or the other, given time and/or sufficient evidence), but that we can never know.
I am reminded in this of J B S Haldane's famous remark: "My own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose. "