I've had many respectful conversations with them and you can see the eyes glaze over when the cognitive dissonance kicks in.
Well, many don't want to be "helped". I haven't spoken to many of them as you seem to have. I know a few however, my first stop on the way out of dubdom was in a nondenominational "Bible-based" house-church. I met with them for a time. I still meet with them very occasionally because they have become my good friends. Out of respect I haven't really engaged many of them on these issues.
I think the best way to speak is to speak from their own traditions, their own book, and from their own understanding. A reconciliation.