CHURCH. "The structure of Truth and Love; whatever rests upon and proceeds from divine Principle The Church is that institution, which affords proof of its utility and is found elevating the race, rousing the dormant understanding from material beliefs to the apprehension of spiritual ideas and the demonstration of divine Science, thereby casting out devils, or error, and healing the sick." Mary Baker Eddy, Science and Health

The First Church of Christ Scientist, Boston, Massachusetts was erected in 1894

"The church, more than any other institution, at present is the cement of society, and it should be the bulwarks of civil and religious liberty. But the time cometh when the religious element, or Church of Christ, shall exist alone in the affections, and need no organization to express it." Mary Baker Eddy, Christian Science Journal, July 1894 

Organ, inside the original edifice

In the December 1893 Journal  Mrs. Eddy stated the church must be built in 1894

"Saturday the 29th (of December 1894) was a busy day.... There seemed to be an enormous amount of work to be done...but we were not the army of retreat. One (Mrs. Eddy) in Concord was demonstrating and we felt the support of this.

At four o'clock that afternoon the last stone was laid, which was the keystone of the arch over the entrance to the lower vestibule. This completed the exterior of the building. At five o'clock that afternoon an immense amount of work had been done but there remained about a hundred and fifty days' work to be done...

We had many mechanics there representing all the different trades, who were willing helpers, and together with them we had many Scientists, - ladies and gentleman who came into dust, clean and do anything they could to make ready for the opening of the church. The work went on quietly but rapidly. The clock struck twelve. In looking about the auditorium floor and gallery I noticed a great procession of men and women walking towards the vestibule. I was surprised. Every person in that room finished his work at the same moment. There were cleaners, carpenters, brick layers, electricians and so on, - all manner of work going on, all the same moment,- for the work was done and the room was ready for occupancy.

Mrs. Eddy's demonstration was complete to the minute. Years afterward it came to me; the picture of that procession walking by unanimous consent to put away their tools and implements which they had used in finishing the room. Nothing was said: no one said, "Time is up;" voluntarily they took their course and laid their tools away. I shall never forget the panorama which presented itself before me. I shall never forget the lesson in precision that it taught me. It was worth all the weeks I had spent in Boston." From Mr. Bates' reminiscences in The Founding of Christian Science - the Life of Mary Baker Eddy written by Doris Grekel page 213-214

"It has often been asked, Why did Mary Baker Eddy found a separate denomination? Why did she not remain in the old church and help it with whatever good she had discovered?

Originally Mrs. Eddy had no plans for establishing a new denomination, for, as I heard her say many times, she confidently expected that the Christian church would welcome her discovery and adopt the healing ministry as an integral part of its activity, even as the early church for three centuries after the resurrection had utilized spiritual means to heal the sick. Indeed, some of her early students spoke in their own prayer meetings of their increased faith in the efficacy of prayer to heal the sick as well as the sinning. But these members frequently were informed by the officers of their churches that such testimony was not welcome, and were advised not to indulge in such blasphemy.

The reception which her discovery encountered in the church was not foreseen by Mrs. Eddy, for she had hopefully looked forward to its immediate acceptance, as is seen by her own words: "Until the author of this book learned the vastness of Christian Science, the fixedness of mortal illusions, and the human hatred of Truth, she cherished sanguine hopes that Christian Science would meet with immediate and universal acceptance." (Science and Health p.330) But this "universal acceptance did not occur; so the healing of Christ Jesus came unto its own but its own received it not. The orthodox church was not ready to restore healing to its ministry.

It was only natural, then, that Mrs. Eddy and her followers should seek to have a church of their own which would permit them to reestablish Jesus' healing ministry by doing his works."  Irving Tomlinson: Twelve years with Mary Baker Eddy.