Wendy Kaminer, author and Humanist who said, “I don't spend much time thinking about whether God exists. I don't consider that a relevant question. It's unanswerable and irrelevant to my life, so I put it in the category of things I can't worry about.”
Adam Savage, Humanist and co-host of MythBusters in a recent talk to the Harvard Humanist said “If you want to believe, or find solace in believing, that someone or something set these particular dominoes in motion—a cosmic finger tipping the balance and then leaving everything else to chance—I can't say anything to that. I don't know.” He goes on to say “Though a primary mover is the most complex and thus (given Occam's razor) the least likely of all possible solutions to the particular problem of how we got here, I can't prove it true or false, and there's nothing to really discuss about it.” The rest of his talk is about personal responsibility from a Humanist perspective.
Even Dewey from Malcolm in the Middle thought the existence of God was irrelevant. He concludes, “I guess all we can do is live our lives with as much kindness and decency as possible. And try not to dwell too much about God standing over us with that giant shovel.” Ahhh, Humanism.