“What I was confused about, was he said nominally, he was a Christian. I don’t know exactly what that means.”
If he is using the word correctly, it means “in name only”, or in other words, not actually a Christian.
Well, that is what I thought too. I was just trying to be diplomatic about it. I don't doubt he saw something, but it looks like he has been deceived. I hope he finds the truth before he checks out for good.