Yes - your experience is very common and probably like a lot of people’s here. About 50% of people who have psychosis don’t have the ability to understand that they have it. The sooner that your wife gets help, the better the long term prognosis.
I recommend you read some of the older posts in this forum and you’ll see its a common issue - here is one:
I also recommend you read and watch this info below:
Try to get him to go with you to see a psychiatrist or psychologist - find something that he can agree with you to see him about - it might be sleep issues, or stress, or anxiety or depression or not feeling good… just get him in there, prewarn the psychiatrist and share a much as you can with the psychiatrist before hand.
Here are some resources - do you have other family members that can help you. Educate everyone, and keep a journal about your brother’s behaviors and beliefs so that you can share it with the mental health professionals.
Study this document:
FIRST Aid for Psychosis
How to get help:
Here is a good place to get your father to, if you can:
I recommend you watch these videos:
I Am Not Sick, I Don’t Need Help! - Dr. Xavier Amador - Pt. 1
I Am Not Sick, I Don’t Need Help! - Dr. Xavier Amador - Pt. 2