Hey again DannyB - I think coming out and telling them that there is no God will not help the situation at all - I left the witnesses but I still believe in God. You said that believing in a God doesn't mean he exists, likewise not believing in him doesn't make him non-existent.
If they are very happy with others doing the thinking for them & they are not questioning, then you are going to have an extremely tough time trying to reason with them. I couldn't stand being told what to think any more, as I told the elders in my JC that 14 old men sitting in Brooklyn Bethel didn't know what *I* needed. All they said to that was that it was 14........
Another suggestion to get them out or to start them thinking for themselves is to approach them as if you need help on say - who really are the faithful & discreet slave - let them do research, you come out with your research and compare the two - ask questions that will get them thinking. Or try use the 607bce approach which blows 1914 out the window....but do it under the guise of you need help.