As a Christian who keeps Saturday as the Sabbath (Friday sunset to Saturday sunset), I am sometimes a source of bewilderment to others not familiar with my beliefs. They persistently think that I am either a Jew or a Seventh-day Adventist. I am neither. But in the eyes of many, these are the only religions observing the Seventh-Day Sabbath.
Most people have heard of Orthodox, Conservative, and Reform Jews. The well-known Seventh-day Adventists number in the millions. Yet most Seventh-day Adventists know little or nothing of the hundreds of other Sabbath-keeping groups who believe the Messiah has come. For a listing, with addresses and in many cases a summary of their distinctive doctrines, write for the Directory of Sabbath-Observing Groups, from the Bible Sabbath Association, 3316 Alberta Drive, Gillette, WY 82718.
Seventh-day Adventists should know more about others who hold very similar beliefs. Their fellow Sabbath-keepers live in the same communities as Adventists, yet in many cases neither knows about the existence of the other. Both know little about the doctrinal beliefs or the history of the other. This is really not too surprising. The typical Protestant or Catholic knows little about the history and doctrines of his own denomination, let alone that of another. Few will bother to know what their church believes, fewer still will find out what others believe.