Warren Edward Buffett (born August 30, 1930) is an American investor, businessman, and philanthropist. He is one of the most successful investors in history, the primary shareholder and CEO of Berkshire Hathaway, and in 2008 was ranked by Forbes as the richest person in the world with an estimated net worth of approximately $62 billion.
Buffett is often called the "Oracle of Omaha" or the "Sage of Omaha" and is noted for his adherence to the value investing philosophy and for his personal frugality despite his immense wealth. Buffett is also a notable philanthropist, having pledged to give away 85 percent of his fortune to the Gates Foundation. He also serves as a member of the board of trustees at Grinnell College. In 1999, Buffett was named the top money manager of the twentieth century in a survey by the Carson Group, ahead of Peter Lynch and John Templeton. In 2007, he was listed among Time's 100 Most Influential People in the world.
In an article in WIRED about Warren Allen Smith, the creator of the website Philosopedia, it discusses how Smith has spent 6 decades writing people to ask if they believe in God. He's received a variety of responses and Buffett's came back, scrawled on a postcard with a one word answer: "Agnostic". 
"He did not subscribe to his family's religion. Even at a young age he was too mathematical, too logical, to make the leap of faith. He adopted his father's ethical underpinnings, but not his belief in an unseen divinity." --from Buffett: The Making of an American Capitalist, by Roger Lowenstein (Doubleday, 1995), page 13.
CNBC 8:45 AM (5-2-2011) on Squawk Box in an interview with Warren Buffet and in response to questions about the value of the US Dollar, Warren Buffet stated, "On the back of the U.S. Dollar it says 'In God We Trust.' If Elizabeth Warren were in charge of the government printing office, I think it would have to say 'In Government We Trust.' Because that is all there is behind paper money.
On HBO Special, 'Becoming Warren Buffet', Warren was asked, "Do you fear death?" and Warren said "No I don't. I've had a terrific life, it's gonna happen. I don't know what happens after death, I'm an agnostic. It may be terribly interesting, it may not be interesting at all."