Unfortunately you can't really do much to correct the average jdub ... as they're well entrenched in their own belief system and anyone trying to prove otherwise, is merely proving the jdub theory that the end is nigh and they're being persecuted.

Have a read through the Tell your JW Story Board part of the forum HERE and you'll get a wider view of why people leave.

For me personally it was more a case of being born and raised in a religion that I inherited from my jdub folks.    I stopped believing when I was around 12'ish and had to bide my time until I was old enough to get a job and live my own life.    Boring story compared to others.    I hope you can gain a better understanding of the jdubs you do come across ... they're  not truly evil per se ... but many are following on blindly and are not used to thinking for themselves.

"Thanks to God .... for making me an Atheist!"
Ricky Gervais
Golden Globe Awards - 2011