The Space Review has posted an article about Russian teacher and librarian, Nikolai Fedorov. Fedorov was an Orthodox Christian that advocated a common task of ancestor resurrection for all humanity. Some of his writing, translated into English, is available on the Internet. Living in the 1800s, Fedorov was a contemporary of Joseph Smith and Brigham Young, but I'm aware of no reason to suppose that they knew anything about each other. That's too bad. Their thoughts about our duties toward our ancestors have much in common, and perhaps could have benefitted from exposure to each other.