They may just have a different system of axiomatic beliefs and are stuck in their own inconsistent state (per godels incompleteness theorem). I actually think most 'disagreements' fall into this fundamental 'human condition' so to speak.

Invoking Godel to assert that people have inconsistencies in their personal beliefs is like using a DNA test to determine whether an animal is an elephant or not - technically correct, but absurd overkill for the task at hand.