Let them be.
Fuck me, I got a family member who claims to believe this shit.
What do you say to a person who just reads a book and then believes it?
It's impossible to sway someone who firmly believes in something. All you can really do is lay down the facts and see if that's enough for the person to change their views.
You already know that there are some people who will believe something to the point of irrationality(religion) and can't be swayed even if the facts say otherwise. It's like telling a viking that the earth is round.
Empire (09-29-2015)
"Finding truth is difficult and the road to it is rough.
As seekers after truth, you will be wise to withhold judgment and not simply put your trust in the writings of the ancients.
You must question and critically examine those writings from every side.
You must submit only to argument and experiment and not to the sayings of any person.
For every human being is vulnerable to all kinds of imperfection.
As seekers after truth, we must also suspect and question our own ideas as we perform our investigations, to avoid falling into prejudice or careless thinking.
Take this course, and truth will be revealed to you."
-Al Hazen
tl;dr question and think about things from all sides, take this course of actions and truth will be revealed
Lunatic (10-11-2015)
Ignorant, you call them ignorant.
If they can prove how a dinosaur bone (millions of years old) came to be about since according to them, the earth is only 6000 years old.