From what you described , he is experiencing a psychosis-hallucinations and delusions. That being said there are millions of people who are psychotic and pose no danger to society. Lincoln, and Ernest Hemingway, as well as many other famous people etc. were thought to be bipolar. So unlessl his hallucinations and delusions involve danger to others, which you have not indicated, there is no reason to believe he is a menace to society.
If you require further clarification or more information, feel free to ask!