As a deeper explanation as to why I personally believe my question to be of a 'silver bullet' nature (of which I believe I posted a topic of this sort a good while back) is as follows.
Just for clairification, I would like to add this little bit to my question, there was something I forgot to add. The full question is as follows
Can you provide comprehensive evidence using the Bible alone that proves an invisible Jesus Christ descended from heaven in 1919 and chose the Watchtower for a divine mission to warn the world of coming destruction?"
The reason I like this question so much is because the opening premise is one that the Jehovah's Witness readily accepts. Just hink about the opening phrase:
Can you provide comprehensive evidence using the Bible alone...
Any Jehovah's Witness who hears the phrase 'prove this to me using the BIble alone' will jump for joy at the opportunity. They believe they can prove all things using the Bible alone.
The trouble is that of course they have many beliefs that have nothing to do with the BIble. Now personally I don't really care what they base their beliefs on. I'm not saying they are a lesser religion because they rest belief on made up stories from the 1930's. But to a Jehovah's Witnesses this is a big deal. They have to prove everything using 'the bible alone'.
No Jehovah's Witness is trained to defend the 1919 teaching. Most may not even realize the scope of it. But their claim is so very clear. An invisible Jesus Christ supposedly came down from heaven and chose them as the only religion on earth that was true. An invisible Jesus Christ! They don't even have a story were somebody had a vision or something!
For a person that has bought into the Watchtowers idea of the 'pagan Trinity', the 'error of hellfire', 'apostate Christendom', the name Jehovah or anything else these ideas about invisible Jesus in the 1910's may be something you are willing to possibly consider. But if you are just some guy who is having his first discussion with a Jehovah's Witness, the last thing that JW wants to talk about is his more exotic beliefs. Rather, he wants to build you up to the point were you'll just accept such stuff without any evidence.
So in essence you are taking their most fanciful and exotic teachings, things they typically hold back from new members, and put them out there are the #1 thing you want them to answer to. They are not used to dealing with this, and it can result in a huge disconnect.
I know it's somewhat of a loaded question, but it has so much potential. No other question (or series of questions) comes at a JW faster. I'll also add that this question gives you the ability to simply sit back and let the JW dig his own hole. You simply asking for the evidence. If he starts to talk about hellfire, just redirect him and say you don't want to talk about that, you want to talk about invisible Jesus in 1919. The point should be clear.
That's at least how I view it.