@Are0h I know it's difficult to see that kind of thing and not want to tell them what time it is, but they have these simple but effective rhetorical tricks. For example, if you try to tell them the truth, they say something like "well if that's true then why are you so defensive?"
The secret to effectively shutting them down is to not let them force you into playing defense. But at the same time you can't let them see you get mad, because they will use that agianst you too.
The answer is to go on the attack, but not with insults or threats. With Socratic questions. It sounds too simple, but it is actually very effective. Ask them questions like:
What exactly do you believe?
How confident are you about that?
How do you know that the thing that gives you the confidence is a reliable method?
If you found out that thing was wrong, would you change your mind?
or my favorite-
My friend says something different. How can I tell which of you is correct?
They *will* try to side-step and distract you, but for this to work, you must be focussed. The first question they don't want to answer, that's the one you keep asking and asking and asking. Keep asking the question until they either answer it or they let everyone see their true colors.
This method is based on #StreetEpistemology but #streetEpistemology is non-confrontational, and I'm all about being confrontational with evil, so I call this method Weaponized Street Epistemology