For some reason, religion seems to invoke credulousness in people.
From the economist.com
When enemies trick him into thinking that his employer loves him, his credulousness is theatrical bliss.
From the bloomberg.com
The credulousness that has caused people to turn to a god is so universal that it must be in our DNA.
From the scienceblogs.com
It's a monument to human ingenuity and credulousness.
From the newscientist.com
Forgeries depend on credulousness as much as craft.
From the theatlantic.com
Credulousness is not confined to sweet old ladies.
From the economist.com
That introduces a more conventional news approach with problems of its own, not least its emphasis on and over credulousness towards official sources and decision makers.
From the guardian.co.uk
More examples
Tendency to believe too readily and therefore to be easily deceived
The characteristic or state of being credulous; credulity