Expose their thinking pattern. When they say "that doesn't apply" tell them "it does apply, but you tell yourself it doesn't apply so you don't have to face up to it, and that's OK if it works for you, but I no longer choose to deceive myself."
Tell them that they don't believe the bible, they believe what Brooklyn NY tells them. If the GB said "new light, the Trinity is true!" then they would reverse a lifetime of beliefs and believe the trinity. Tell them you now think for yourself, which is why you can defend your beliefs.
Pick a topic that is completely unwinnable for them, like the overlapping generations, or the new scrolls, and every single time they start to criticise you, just go back to that topic with "until you can explain the new scrolls to me, I'm not going to discuss anything else with you. Can you explain it yet, or is it a false teaching?"
They will soon be on the defensive, and you won't ever get angry again.