Interfaith Group

I would use the argumentation tactics of classical debate and nihilism.

1. Define terms. What is a deluded belief? Check to see if the definition is fair. For example, "deluded belief = any religious belief" would circular in nature, and similar to "the Bible is true because the Bible says it's true."

2. How should we use this definition to determine if any one belief is deluded or not? If this question is not answered, then call bullshit. If we do not have a system for a label, then the label is completely arbitrary. It won't even have the bias of science, which assumes there is an objective world.

3. Apply this definition to a variety of other beliefs. For example, slavery is bad, money has value, the POTUS has authority, a historic event has actually occurred, objects exist, you are not a brain in a jar, etc. This should be done thoughtfully.

4. You will likely expose the flaws, if there are any, in their arguments using this method, but very few people will be willing to clearly defend their position. Most people resort to insults and/or strawmen pretty quickly, in my experience.

Just my opinion.