Has hallucinations and delusions about the devil but he does know himself. Does he have paranoid schizophrenia?

Not all psychosis is due to schizophrenia.

There can be similar delusions in severe depression, bipolar disorder, drug use (esp cocaine, stimulants) and other metabolic disorders, syphyllis, and brain leisons. Early evaluation and treatment is essential for a good outcome. Would you like to video or text chat with me?