It's like arguing with a brick wall. No amount of evidence matters if someone refuses to hear it. Anyway, how about this?
" Brother Rulemaker and Brother Mc Timechecker, do you belive that at one time the Nation of Israel was God's Organization?", " Why of course it was Brother Weak." , " Ok, would it be fair to say that God was using the Nation of Israel at that time?" , " Well, errrr...Yes, of course.", " Had you lived back then, would you have owed your salvation to the Nation of Israel or to Jehovah?" , " Jehovah of course." , " Would you have obeyed Jehovah even if the High Priest asked you to do something Jehovah disapproved of?" , " Well, no..of course not ", " What if the High priest labled you as an apostate?" , " We would obey Jehovah no matter what!" ..............
I doubt that we could ever get even that far in reasoning with them. The only times that I have ever seen a conversation go on that long, is when they are under oath in court and forced to answer, like in the Walsh case. Even in court they will lie for the Organization. You can't win.