In Rabbi Yisroel Meir Lau’s Yachel Yisroel Hagada shel Pesach, the former Chief Rabbi of Israel and current Chief Rabbi of Tel Aviv tells the following:
During the first wave of immigration from the Soviet Union, I was the Chief Rabbi of Tel Aviv-Yaffo. One day, as I sat in the beis din that does conversions, a 42 year old doctor came in. He had come from the Soviet Union the day before with his wife and two daughters. He came for documents affirming his Jewishness for all the institutions that required it. He even brought witnesses with him to testify that he was Jewish, a son of Jewish parents. His mother was a pediatrician who runs a cardiology department in Moscow and his father, who was no longer living, had been a surgeon.
One of the witnesses said he had been present at the bris of this young doctor, George, 42 years ago. What he said next astounded everyone in the room. He was a Lubavitcher, an older person, who came to the beis din wearing a kasket (cap) and had a long white beard. He said the mother of this George who runs a department in a hospital was a heavy smoker who smoked two to three packs a day. But every night, before she went to sleep, she would take one cigarette and put it in the closet in her bedroom in a box. Every night, one cigarette.
Once a year, after Purim, I (the Lubavitcher) would go to her, and it was an agreement we had – she would give me 350 cigarettes that had accumulated over the year and I would give her a few kilograms of flour so she could bake matzos for Pesach. She did not keep Shabbos, did not keep kosher, but she was particular about having a seder in her house and that the house should mark the exodus from Egypt with all the symbolism involved.
I (R’ Lau) was very moved by the story. The son gave me her phone number in Moscow. I called her and she could still speak some Yiddish. I said to her, “We do the mitzva of matza once a year. You fulfill it every single night, 350 days a year. I don’t know whether your matzos were halachically kosher but they were certainly holy and pure and accepted graciously by G-d; I have no doubt about that!”
I kept her on the phone and I said to her son in English, “George, from today on, we are brothers, but to me you aren’t George, but Gershon.” She apparently wiped away a tear and said to me, “That is his name, Gershon. His father gave him that name at his bris 42 years ago.”