Ella Wheeler Wilcox best-known work was Poems of Passion. Her most enduring work was " Solitude", which contains the lines: "Laugh, and the world laughs with you; Weep, and you weep alone". Her autobiography, The Worlds and I, was published in 1918, a year before her death.

In 1884, she married Robert Wilcox of Meriden, Connecticut, where the couple lived before moving to New York City and then to Granite Bay in the Short Beach section of Branford, Connecticut. The two homes they built on Long Island Sound, along with several cottages, became known as Bungalow Court, and they would hold gatherings there of literary and artistic friends.[1] They had one child, a son, who died shortly after birth. Not long after their marriage, they both became interested in theosophy, new thought, and spiritualism.

Early in their married life, Robert and Ella Wheeler Wilcox promised each other that whoever went first through death would return and communicate with the other. Robert Wilcox died in 1916, after over thirty years of marriage. She was overcome with grief, which became ever more intense as week after week went without any message from him. It was at this time that she went to California to see the Rosicrucian astrologer, Max Heindel, still seeking help in her sorrow, still unable to understand why she had no word from her Robert. She wrote of this meeting:

In talking with Max Heindel, the leader of the Rosicrucian Philosophy in California, he made very clear to me the effect of intense grief. Mr. Heindel assured me that I would come in touch with the spirit of my husband when I learned to control my sorrow. I replied that it seemed strange to me that an omnipotent God could not send a flash of his light into a suffering soul to bring its conviction when most needed. Did you ever stand beside a clear pool of water, asked Mr. Heindel, and see the trees and skies repeated therein? And did you ever cast a stone into that pool and see it clouded and turmoiled, so it gave no reflection? Yet the skies and trees were waiting above to be reflected when the waters grew calm. So God and your husband's spirit wait to show themselves to you when the turbulence of sorrow is quieted.

Several months later, she composed a little mantra or affirmative prayer which she said over and over "I am the living witness: The dead live: And they speak through us and to us: And I am the voice that gives this glorious truth to the suffering world: I am ready, God: I am ready, Christ: I am ready, Robert.".

Wilcox made efforts to teach occult things to the world. Her works, filled with positive thinking, were popular in the New Thought Movement and by 1915 her booklet, What I Know About New Thought had a distribution of 50,000 copies, according to its publisher, Elizabeth Towne.

The following statement expresses Wilcox's unique blending of New Thought, Spiritualism, and a Theosophical belief in reincarnation: "As we think, act, and live here today, we built the structures of our homes in spirit realms after we leave earth, and we build karma for future lives, thousands of years to come, on this earth or other planets. Life will assume new dignity, and labor new interest for us, when we come to the knowledge that death is but a continuation of life and labor, in higher planes".