Brother:
There is no point in arguing with heretics.
"Cast not your pearls before swine, lest they turn and rend you!"
You have tried to tell them the truth.
Tex...you've quoted Matthew 7:6 a few other times as I recall. It must be one of your favorites. Do you remember what Jesus said in Matthew 7:1-3?
[Do not judge, or you too will be judged. For in the same way you judge others, you will be judged, and with the measure you use, it will be measured to you. Why do you look at the speck of sawdust in your brother's eye and pay no attention to the plank in your own eye?]
Blessings to you and yours.
Diego