Some don't want to be taught. I was having a conversation with a fellow the other day who had set out to convince me that the DaVinci Code is true. I pointed out all the historical errors to him, and his response was 'oh you are just brainwashed.'
He did not wish to know the truth.
yep, and your responsibility and authority ended with his exercise of volition. He didn't change your knowledge of the truth, and you didn't change his. Next...
Seriously, one can do one's best, but ultimately we are all responsible for exercising our own volition.
Some people will believe anything except the truth and Da vinci isn't it.