I was walking down the stairs by the Kotel to go for mincha. I noticed this unusual looking man having his picture taken while he was touching the big mezuzah that is attached to the tunnel entrance. He was wearing a kipa and tzitzis, but he did not look Jewish, not at all. I wondered if he was a ger or maybe an overly enthusiastic Ben Noach.
About an hour later he walked by the tefillin stand and I asked,
"Where are you from?"
"What's your name?"
"Are you a convert?"
"You're not Jewish, are you?"
"A Ben Noach?"
"A righteous gentile who keeps the Commandments of Noach."
"No. I'm messianic."
That explained it all. A "messianic" is a gentile who believes that yushka was the moshiach (messiah). They try to mix the little bit they have read about Judaism with x-ianity. There is no way to change their belief… well not on the spot, but you can give them information that later, when they are ready, when a few more challenges come to their irrational beliefs will help them to move away from that foolishness.
"Let me ask you a question. You read the Bible, right?"
He nodded, yes.
"In the Bible it says that the messiah has to be from King David's tribe. That's the tribe of Judah."
He nodded that he agreed.
"And the Bible clearly says that the tribes go by the father; whatever tribe a Jew's father is from, that Jew is also from that tribe."
He was okay with that… until the next sentence.
"Now who was your messiah's father? I read your book. It wasn't anyone from the tribe of Judah."
They believe that yushka was born from a virgin mother, that there was no man involved, that his mother was impregnated by the "holy ghost"!
"There are no ghosts in the tribe of Judah!"
"You gave me something to think about," and he turned and walked away.
Almost always, when a x-ian is challenged he walks away.
The truly sad thing about them is that they really want to do good, but someone has sold them a bill of counterfeit information.