Mrs. Gestefeld gave herself totally to the practice and teaching of Christian Science. A very talented teacher, she soon had a substantial following.

But all too soon she demonstrated a greater ability than Mary Baker Eddy which inspired Eddy's jealous rage. The final straw for Eddy was that Ursula wrote her own book in 1888, titled, "Ursula N. Gestefeld's Statement of Christian Science." Despite the fact that unlike Eddy, Gestefeld actually credited her teachers, Eddy was filled with rage that a "pupil" would dare to write anything. Eddy felt she was the only person qualified to dispense any wisdom about "Christian Science"and so she denounced Mrs. Gestefeld in the Christian Science Journal and excommunicated Ursula from her church.

Once again Eddy had attacked a talented mystic. Unlike Emma Curtis Hopkins, Gestefeld reacted to Mrs. Eddy's attack upon her with a pointed pamphlet titled Jesuitism in Christian Science. She was expelled from the association, which spurred her on to greater success. Mrs. Gesterfeld's career as teacher and practitioner of true New Thought was launched, eventually becoming recognized as a leader in the Divine Science movement which came to be called New Thought.

A great deal of Ursula's work was in Chicago where she regularly taught classes, maintained a center, published books and wrote in magazines as a means of sharing her ideas and the ideas of others in the early New Thought Movement. To the system which she eventually evolved, she gave the name "Science of Being."