Wonderful point, Sea Breeze; short, clear, to the point, using sincere questions not statements!
When I was a jw, that would have been an aha moment for me to have those dots connected.
I asked them who introduced the concept of two classes of Christians having separate hopes, when Ephesians 4:4 says that all Christians are called to “one hope?”
They said they would have to do some research
Once you get a JW to admit that the Watchtower has added a hope (or gospel) that was unknown or not taught by the apostles, then you can read to them Galatians 1: 8 and ask them if this verse concerns or alarms them at all.
" though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. " - Galatians 1:8
Ask them, "you don't really want to be cursed by God do you"?
This verse destroys the false Watchtower teaching of "new light."