Address the inconsistencies between there behavior and what they say to believe.
Address inconsistencies and contradictions in the claims they believe.
Remember that not knowing a answer to something doesn't mean you should accept the claims of another if they don't have proof to support it.
When making claims about scients, morals etc. stick to logic and facts. they might not get through and the other guy might repeat him self. If he does address it and remind him you'v already debunkt that point so he should know its not true and that clinging to it is just a sign of dishonesty.
Address inconsistencies and contradictions in the claims they believe.
Remember that not knowing a answer to something doesn't mean you should accept the claims of another if they don't have proof to support it.
When making claims about scients, morals etc. stick to logic and facts. they might not get through and the other guy might repeat him self. If he does address it and remind him you'v already debunkt that point so he should know its not true and that clinging to it is just a sign of dishonesty.