Eddy separated from her second husband Daniel Patterson, after which she boarded for four years with several families in Lynn, Amesbury, and elsewhere.
Frank Podmore wrote:
But she was never able to stay long in one family.
She quarrelled successively with all her hostesses, and her departure from the house was heralded on two or three occasions by a violent scene.
Her friends during these years were generally Spiritualists; she seems to have professed herself a Spiritualist, and to have taken part in séances.
She was occasionally entranced, and had received "spirit communications" from her deceased brother Albert.
Her first advertisement as a healer appeared in 1868, in the Spiritualist paper, The Banner of Light.
During these years she carried about with her a copy of one of Quimby's manuscripts giving an abstract of his philosophy.
This manuscript she permitted some of her pupils to copy.

After she became well known, reports surfaced that Eddy was a medium in Boston at one time.
At the time when she was said to be a medium there, she lived some distance away.
According to Gill, Eddy knew spiritualists and took part in some of their activities, but was never a convinced believer.
For example, she visited her friend Sarah Crosby in 1864, who believed in Spiritualism.
According to Sibyl Wilbur, Eddy attempted to show Crosby the folly of it by pretending to channel Eddy's dead brother Albert and writing letters which she attributed to him.
In regard to the deception, biographer Hugh Evelyn Wortham commented that "Mrs. Eddy's followers explain it all as a pleasantry on her part to cure Mrs. Crosby of her credulous belief in spiritualism."
However, Martin Gardner has argued against this, stating that Eddy was working as a spiritualist medium and was convinced by the messages.
According to Gardner, Eddy's mediumship converted Crosby to Spiritualism.

In one of her spiritualist trances to Crosby, Eddy gave a message that was supportive of Phineas Parkhurst Quimby, stating "P. Quimby of Portland has the spiritual truth of diseases.
You must imbibe it to be healed.
Go to him again and lean on no material or spiritual medium."
The paragraph that included this quote was later omitted from an official sanctioned biography of Eddy.

Between 1866 and 1870, Eddy boarded at the home of Brene Paine Clark who was interested in Spiritualism.
Seances were often conducted there, but Eddy and Clark engaged in vigorous, good-natured arguments about them.
Eddy's arguments against Spiritualism convinced at least one other who was there at the time—Hiram Crafts—that "her science was far superior to spirit teachings."
Clark's son George tried to convince Eddy to take up Spiritualism, but he said that she abhorred the idea.
According to Cather and Milmine, Mrs. Richard Hazeltine attended seances at Clark's home, and she said that Eddy had acted as a trance medium, claiming to channel the spirits of the Apostles.

Mary Gould, a Spiritualist from Lynn, claimed that one of the spirits that Eddy channeled was Abraham Lincoln.
According to eyewitness reports cited by Cather and Milmine, Eddy was still attending séances as late as 1872.
In these later séances, Eddy would attempt to convert her audience into accepting Christian Science.
Eddy showed extensive familiarity with Spiritualist practice but denounced it in her Christian Science writings.
Historian Ann Braude wrote that there were similarities between Spiritualism and Christian Science, but the main difference was that Eddy came to believe, after she founded Christian Science, that spirit manifestations had never really had bodies to begin with, because matter is unreal and that all that really exists is spirit, before and after death.
Eddy separated from her second husband Daniel Patterson, after which she boarded for four years with several families in Lynn, Amesbury, and elsewhere. Frank Podmore wrote:
But she was never able to stay long in one family. She quarrelled successively with all her hostesses, and her departure from the house was heralded on two or three occasions by a violent scene. Her friends during these years were generally Spiritualists; she seems to have professed herself a Spiritualist, and to have taken part in séances. She was occasionally entranced, and had received "spirit communications" from her deceased brother Albert. Her first advertisement as a healer appeared in 1868, in the Spiritualist paper, The Banner of Light. During these years she carried about with her a copy of one of Quimby's manuscripts giving an abstract of his philosophy. This manuscript she permitted some of her pupils to copy.
After she became well known, reports surfaced that Eddy was a medium in Boston at one time. At the time when she was said to be a medium there, she lived some distance away. According to Gill, Eddy knew spiritualists and took part in some of their activities, but was never a convinced believer. For example, she visited her friend Sarah Crosby in 1864, who believed in Spiritualism. According to Sibyl Wilbur, Eddy attempted to show Crosby the folly of it by pretending to channel Eddy's dead brother Albert and writing letters which she attributed to him. In regard to the deception, biographer Hugh Evelyn Wortham commented that "Mrs. Eddy's followers explain it all as a pleasantry on her part to cure Mrs. Crosby of her credulous belief in spiritualism." However, Martin Gardner has argued against this, stating that Eddy was working as a spiritualist medium and was convinced by the messages. According to Gardner, Eddy's mediumship converted Crosby to Spiritualism.
In one of her spiritualist trances to Crosby, Eddy gave a message that was supportive of Phineas Parkhurst Quimby, stating "P. Quimby of Portland has the spiritual truth of diseases. You must imbibe it to be healed. Go to him again and lean on no material or spiritual medium." The paragraph that included this quote was later omitted from an official sanctioned biography of Eddy.
Between 1866 and 1870, Eddy boarded at the home of Brene Paine Clark who was interested in Spiritualism. Seances were often conducted there, but Eddy and Clark engaged in vigorous, good-natured arguments about them. Eddy's arguments against Spiritualism convinced at least one other who was there at the time—Hiram Crafts—that "her science was far superior to spirit teachings." Clark's son George tried to convince Eddy to take up Spiritualism, but he said that she abhorred the idea. According to Cather and Milmine, Mrs. Richard Hazeltine attended seances at Clark's home, and she said that Eddy had acted as a trance medium, claiming to channel the spirits of the Apostles. 
Mary Gould, a Spiritualist from Lynn, claimed that one of the spirits that Eddy channeled was Abraham Lincoln. According to eyewitness reports cited by Cather and Milmine, Eddy was still attending séances as late as 1872. In these later séances, Eddy would attempt to convert her audience into accepting Christian Science. Eddy showed extensive familiarity with Spiritualist practice but denounced it in her Christian Science writings. Historian Ann Braude wrote that there were similarities between Spiritualism and Christian Science, but the main difference was that Eddy came to believe, after she founded Christian Science, that spirit manifestations had never really had bodies to begin with, because matter is unreal and that all that really exists is spirit, before and after death.
Mary Baker Eddy