We aren't even friends what should I do?

I met my husband when we were teenagers. Back when we dating one time he brought a church friend named Emanuel. We briefly spoke. I only include his first name because it impacts is delusions. I've been married 20 years at this point, I'm 40 now. I haven't been in the same room with email in probably 20 years and that is only if he was at church at some other point before I got married. We are not friends, not socially aquatinted in any real way. But he tags me obsessively on social media.

By itself, that's not a big deal, but over the past 5 years he has become convinced that he is THE Emanuel. None other than the actual Lord Jesus Christ himself. I don't interact or respond. He messages and tags me constantly. He occasionally sends angry messages demanding for my husband to talk to him. He sent me a random photo of his medication and told me he had been diagnosed with schizophrenia. (Again I never responded.) My husband wanted to go see him to make sure he was okay, but I said no. Emanuel believes we have been judged by God because my husband and I won't talk to him. I do want to be physically around him. He lives in the same state, different city but I don't actually know where because WE AREN'T AQUAINTED.

I realize no one chooses schizophrenia. It's a disease. I'm not without compassion, and I'm sure he's lonely and in a lot of ways he misses his old friend. I'm afraid to block him completely on social media because I think I rather have a heads up if he threatens any real violence or self harm, though I know most schizophrenics are absolutely not dangerous. Am I wrong? Is it best just to block him so he can't tag me anymore? Is there a good way to deal with an obsessive schizophrenic who you are not actually involved with beyond being the target of their obsession? Would it be bad to interact or am I making it worse by ignoring him? At this point this person who I have not been involved with for over 20 years is tagging me 5-6 times a day, and not like he's tagging 100 people and I'm one. Sometimes I'm one of 3 or the only one. And the couple of other profiles he's tagging are not actual people. I'm the only real person and it worries me. Should I be worried??