He is Russian and has been living in London for some time. He spoke with an English accent. He's a lorry (truck) driver. We spoke at length to make sure that his mother's mother was really Jewish. He had no idea that this means that he is a Jew. He kept the tefillin on for a long time, stood by the Kotel praying for quite a while, took a bunch of pictures, and was truly excited about the experience.
When I told him that he had to marry a Jewish girl he proudly showed me his brand new wedding band. He just got married two days before. I asked if she was Jewish. He said that she wasn't. I said, "Maybe you can get your money back." He laughed. I told him to check and see if her mother's mother was Jewish.
Again, does doing one mitzvah bring a lost Jewish soul back from an entirely non Jewish life style? It sure will help him at Heaven's Gate when it's time for him to report back in. I bet Hashem will send him another message, and then another, but the bottom line is; what each of us ends up doing and where we end up going is really up to us.