My friend is acting strange and flew the country?

My friend and I have been friends for 3 1/2 years. We met in college in London (we're both Americans) He went back to the states 6 months ago, so we talk online and on the phone from time to time. The last two weeks, he was acting EXTREMELY strange by telling me he wanted to get plastic surgery on his face and that he didn't want to be recognized by his family. He also legally changed his name. Then last week, he just continued to go on and on about how God has blessed him and that we all need to be thankful and that we all need to worship him. I was starting to get worried.

I was at my internship today when I get a phonecall from one of my roommates. When I answer the phone, it's him, telling me he's in London and he's at my house. He said he couldn't take his mother anymore (they argue quite often) and that he flew here. I asked him how he got the money and he said "God helped me." He then told me to hold on a sec and after a few minutes of silence, asked me if I could hear anything. I said no, in which he did it again, and when I said no again, he said it was God talking to me.

He said he plans to stay in London until the end of December and wants to go to Italy afterwards. He has no money and has no friends in the UK. I'm at work right now and I'm really freaked out about going home. What has happened to my friend? And he can't stay with me because I share a house with three other people but I can't put my friend out on the street. I care about him and I worried about him.

What's going on? What should I do?