
Credulity
Easily Deceived
 Credulity implies someone can be easily tricked due to their readiness to believe. 
His credulity left him vulnerable to online scams.
 Not Always Negative
 While often carrying a negative connotation, in some contexts credulity can suggest an open, trusting nature. 
The child's credulity gave life to the fantastical stories.
 Literary Device
 In literature, a character's credulity may be used to introduce plot twists or illustrate a moral lesson. 
The protagonist's credulity led him into the villain's trap.