They were the ones who printed that book, "Millions Now Living will Never Die." That one can be found online, and it is out of copyright. That's a good one to bring up to them--most J.W.s have never heard of that book.
Abraham thought the blessings he was told of through the visiting Angel were going to be expressed through his servant Eliezer, then through Hagar, until he finally got it when he had it explained again that the blessings were coming through his wife, Sarah, having her reproductive abilities restored.
There are several more examples like this in the Bible involving very faithful servants, where a message or teaching was was received and misunderstood because of an enthusiasm to carry it out. The eventual result was what God purposed because of His understanding, patience, and grace towards their imperfect state. Basically, they didn't want to remain wrong, repented, and readjusted.