I asked my dad about Christian Science once. He was an Congregational minister (a very liberal demonination which is now a days called United Church of Chirst). He said "Mary Baker Eddie was a medium who made it." That is, made it to the big time.
At the turn of the century, around 1900, there was a great resurgence of religious and spiritual movements of all sorts. Edger Casey, Mary Baker Eddie, Alaster Crowley, Gurdjiff, etc, etc. Christian Science is one of the few to remain.
It's interesting to look at the birth of recent religions like Mormonism, CS, Scientology. I think they are no different from ancient religions, but the true historical details of the origins of Hinduism or Christianity are long lost. Only their own mythological writings remain, although if you dig hard you can find people who try to study the history and literature of ancient religions objectively.