They do know the honest answer, but don't want to give you any ground in the argument... completely missing the point that by hedging their bets and dissembling, they totally undermine their own position. As of late, I have heard a few comments like "satan is controlling your brain," if I question such things.
Having lived the xian life for 30+ years (I'm spitting on the floor now... 7 months "sober"), I know precious few thesits who had any concept or appreciation for logic (or even identifying when they stepped into a logical fallacy). Why I compartmentalized logic into something else I used in life, but not theism, is a puzzle to me still (long term temporary insanity?).