I am German through my mother, and it was only after she died and through genealogy that I found we are German Jews. Then it was that I found her family name were exterminated, as were cousins by another name.
For me, my brothers and cousins, finding that we were Jewish was the happiest day of our lives. We are of course Christians.
We don't know when the family became Christians, but it was before they came to America in 1846, and I suspect sometime before that due to all the persecutions, joining the Lutheran Church to avoid torture and save their children.