I saw in the "Why is service so lame" thread WTWizard takes the JW's to Ephesians 2:8,9. It reminded me of what I would say when they called. This was when we first moved and they did not yet know me. I would let them say their piece and then I would ask them "Why are you here?" I would get the stranges stares first, and then the odl 'We're doing a life saving work." or something similar. Again I would say "That's nice but why are YOU HERE? Again some canned responce. I would continue until they would say "We have to be here to be saved." Then I to would show them Eph. 2. They would then bring up James 2:17, 20 "Faith without works is dead." (Which is where I wanted them to go)
I would say "That is a good scripture." and ask "Does James give an old testament example there? The would say yes - Abraham. I would then go to Galatians 3 and say that "Paul says we are justified by faith not works and he to uses the odl tastament example of Abraham. How could that be it seems like a contradiction, Does the Bible contradict itself? (Remember I'm speaking to a JW, so that question is for another thread) They would reply "No!" I would then say "You are right, so there must be a reason that two Bible writers used the same OT example to prove opposing points." I would let them respond but they never did. So I would say "Taken in context of the book each was writen in and therefore how the writer intended it to be undestood, there is no contradiction. Paul was saying before God we are justified by faith not works & James said before man we are justified by works. Because men can only see Abrahan raise the knife over Issac's body -works, but God could read Abraham's heart long before he even reached the mountain."
Then I would wrap it all up for them and say "So, you are here because God or the Bible says you have to be here? Or are you here because your church tells you you have to be here." I would then say "Don't answer that question to me, you just think about it to yourself, you read the scriptures in context with the books they were writen in, you do the research, you make the truth your own."