Yeah, that was never enough to keep me believing in the bible. What did it for me was that I never bothered to research the evidence that the book of Daniel was a forgery and written much later than most believers will claim. I know that the prophecies in there about cyrus and alexander the great, etc, are what have many of the more intelligent JWs that I know still stuck mentally believing in the bible. I know one elder in particular, who likes to talk about having been agnostic prior to his wife's indoctrination (he joined not long after) and that's always the proof he cites that the bible is god's word.
They like to go on about the advice being timeless and only god could do that, but unfortunately the advice is only timeless when you cherry pick what suits you. When you have a written work the size of the bible, it's not that difficult to find "timeless advice" in there for most situations.
The cult offers so many different (and all inherently flawed) explanations to convince people that the bible is inspired, but it seems most JWs just hold on to whichever one it is that makes sense to them, and dismiss what seems spurious or too complicated. It's the shotgun approach - give 'em 100 reasons and even if they see through 99 of 'em, the one that sticks will keep 'em trapped.