Ahlulbayt in Quran and blindness to them is best explained by dark magic.

[Angrboda]

It;s entirely likely that his family and/or friends are feeding the delusion on account of it;s simple religious utility.  Turning to them for help may not be the solution you're imagining it is....it might even be what got him into this mess.

I think, with certain mental illnesses, certain themes can be more entrancing, more significant and salient, lending toward an obsession with such themes. I know of myself that when I fail to do something I am otherwise tasked to do, I often have to wonder whether that is an expression of my depression or just the type of person I am. I also know that I've gone through brief periods of weeks where religious themes took on considerable significance and urgency to me, and just as suddenly stopped being so. I think anyone who exists on the schizotypal spectrum of illnesses, such as MK and myself, have to be careful to know that one's involvement with religious themes is just an expression of healthy interest, rather than expressing a susceptibility to obsess about such themes. In the latter case, one's behavior can be unduly influenced by one's illness without technically being mentally ill. I suspect MK falls on this border, that while his commitment to his religion reflects a healthy interest, the degree and way his interest in these themes manifests itself is being unduly influenced by the predispositions he likely has as a person with schizophrenia. (The stream of consciousness narratives, filled with romantic religious imagery, in particular, seem an example.)