This is one of the most common types of delusions, centering around a person’s fixed, false belief that others aim to obstruct, harm, or kill him/her.
See paranoid delusion for more information about this kind of delusion.
Example: A man believes he is the focus of a “vast, right-wing conspiracy” which results in his being spied upon and plotted against.
Grinnell, R. (2012). Persecutory Delusion. Psych Central. Retrieved on October 13, 2015, from http://psychcentral.com/encyclopedia/2008/persecutory-delusion/