The same thing applies to those that do not go to church, but give the auto-response "Yes." when asked if they are Christian. Many of them don't really believe, but never bother to think about it enough to even realize it. Others say they believe, but never think about it at all... ever... unless asked directly (aka: average 'Christian').
Any poll counting the number of believers or members of specific religions are unpredictably skewed by rampant apatheism.
Any poll counting the number of believers or members of specific religions are unpredictably skewed by rampant apatheism.