Christianity by definition

Delusional disorder is a psychiatric diagnosis denoting a psychotic mental illness that involves holding one or more non-bizarre delusions in the absence of any other significant psychopathology (signs or symptoms of mental illness). In particular, a person with delusional disorder has never met any other criteria for schizophrenia and does not have any marked hallucinations, although tactile (touch) or olfactory (smell) hallucinations may be present if they are related to the theme of the delusion.

A person with delusional disorder can be quite functional and does not tend to show any odd or bizarre behavior aside from these delusions. "Despite the encapsulation of the delusional system and the relative sparing of the personality, the patient's way of life is likely to become more and more overwhelmed by the dominating effect of the abnormal beliefs".[2]