David Letterman makes ambiguous statement.
On October 17th, 2013 on The Late Show David Letterman said to his guest Bill O'Reilly "I went to Sunday school and church every day of my life until I was 16, and then I finally said to my folks. Aye I aye sheesh(stuttering and doing shtick) I can't go anymore." Bill responds "Why?" and Letterman says "I don't know. At 16 you get other things on your mind."
As much as we applaud atheist comics George Carlin, David Cross, Ricky Gervais, Seth MacFarlane, & Howard Stern, for bringing their atheism up in their routines, we know It's common for entertainers to keep their atheistic leanings quiet as they may lose some of their audience. Groups like the Family Council and Catholic League have staged boycotts on atheistic entertainers.