If the mind wanted to believe in something soooo much, could the mind make it real for the person?

For example, I have a friend who I entrust with my life, I've known him for about 6 years and we dated a few times, he is one of the smartest and most sane people I know. He is extremely religious though, (Christian) just a really level headed Christian who has never pushed his views upon me. He told me that about a week ago, he had an angel show themselves and spoke to my friend, while he was awake. He swears that it really happened, and that he was awake, and that it was all real. I KNOW for a fact that he would never lie to me, especially over something like this, so do you think it might of been his mind that played tricks on him, or did something really happen? He said it happened while he was praying for it to happen, saying that he was asking God to speak to an angel face to face over something happening in his life, obviously very personal to him for he would not tell me what it was. What do you guys/girls think?