A long time ago, in a galaxy far, far, away... when I was still a young padawan, not yet experienced in the ways of the Jedi, an elder was calling on me, trying to encourage me back to the dark side (KH meetings). I laid out my defense...everything from 607 vs 587 to the beard prohibition not being non supported by scripture.
He was patient, and actually listened. I think I made him squirm on a couple of issues. Finally, I asked him what he would do if learned one day that a WT prediction failed, or that a major doctrine changed. Would he sit up, take notice, and contemplate a change? His answer - No. See, he was a trouble youth before he found the JWs. Gang violence, drugs, theft. But when he started studying, he saw he needed to change. And change he did. He went full bore into JWism. By the time I knew him, he was a family man, with kids and one of the showcase elders in the circuit. Actually, he is a good man, one of the good guy elders. I liked him. Still do. But since this religion had saved him from a life of drugs and crime, he was now in debt to them for them saving his life. He felt even if something was amiss with the WTS, he still owed them. There was no point in going further with our discussions. I wasn't going to change. He wasn't going to change.