Faith at Work would probably never have come into existence as an independent movement if it had not been for the growing influence of The Calvary Evangel, later called The Evangel, a magazine of Faith at Work, and still later simply Faith at Work. The Calvary Evangel started out as the monthly church publication of Calvary Church providing both parish information and fairly traditional inspiration from the time of its inception in 1888 until it was taken over by Sam Shoemaker and his friends in 1925. In 1930, Irving Harris became the Editor of The Evangel on a part-time basis and from that time until Sam Shoemaker's departure for Pittsburgh at the end of 1951, it reflected faithfully the life style and point of view of its leadership. In 1942, the Editor spoke of The Evangel as "a magazine for life changing and spiritual continuance and a regular means of keeping in touch with one another." A superficial analysis of the contents of The Evangel in the period 1925-51 suggests that in addition to serving as a newsletter, the magazine provided two kinds of input:

Shoemaker was born in a rented house on Read Street in Baltimore, Maryland on December 27, 1893 to Samuel Moor Shoemaker, Jr. (later chairman of the Board of Regents of the University of Maryland) and Nellie Whitridge (later President of the Women's Auxiliary of the Episcopal Diocese of Maryland), who had met at Emmanuel Church in Baltimore, where his uncle was rector.

Two years later, the young family moved to his late paternal grandfather's property, 'Burnside', about 10 miles north of Baltimore at the entrance to the Green Spring Valley. In 1898, his father turned Burnside into a dairy farm, with a prize herd of Guernsey cattle, though his grandfather had preferred Jerseys. Sam Shoemaker was well aware of his privileged upbringing: Mennonite Schumachers had moved from Germany, Holland and Switzerland hundreds of years earlier, converted to Quakerism under the influence of william Penn's missionaries and Anglicised their surname as they moved to Germantown, which became a Philadelphia neighborhood. One of his ancestors of the same name had twice served as Philadelphia's mayor, and his paternal grandfather (who died in 1884 and for whom both Sam's father and young Sam were named), although born in Lafourche Parish, Louisiana, made his fortune organizing the Great Western Express transportation line between Philadelphia and Baltimore. His paternal grandmother, the Victorian matriarch who raised him as an Episcopalian, was Augusta Chambers Eccleston, of Chestertown, Maryland, daughter of Maryland Court of Appeals Judge John Bowers Eccleston (1794-1860) and sister of the Rev. John H. E. Eccleston, whose Emmanuel Episcopal Church was decorated with flowers from the family's greenhouses. A more distant John C. Eccleston (1828-1912) served as a priest in Richmond County, New York. Sam's maternal grandfather, John Augustus Whitridge, had a fleet of clipper ships, although he died when Sam was 13. Shoemaker later became known for a slight southern inflection in his speech, which he attributed not to these relatives, but to his lifelong friend Hen Bodley, and to James (actually Richard Hugh Gwathney), a longtime family servant, who had been born in Fredericksburg, Virginia.

Upon graduating in 1912, Shoemaker attended Princeton University, as had his father. A fan of President Woodrow Wilson, Shoemaker became acquainted with the political controversies of the day, and after his sophomore year traveled to Europe. Upon returning, Shoemaker and three other students protested war propaganda and military drills at the university. At Princeton, Shoemaker met Robert Speer, John Mott and Sherwood Eddy through the World Student Christian Federation. He became interested in personal evangelism and missionary work, as well as the relatively new ecumenical movement.

In 1917, with the blessing of the Rt. Rev. John Gardner Murray, bishop of Maryland, Sam Shoemaker went to China to start a branch of the YMCA and teach Business courses at the Princeton-in-China Program. Shoemaker spent several years in China, but attracted few converts until he came under the influence of the Oxford Group and Frank Buchman. A follower of Dr. Mott as well as leader of Penn State's Y group, Buchman advised Shoemaker to look inside himself, and to talk about his personal experiences. Buchman also told Shoemaker about the essence of the Sermon on the Mount being four absolutes: honesty, purity, unselfishness and love. After contemplating his own inadequacy compared to those absolutes, Shoemaker decided to let God guide his life. He returned to Princeton in 1919 to head the Philadelphian Society, a campus Christian organization which he had led during his senior year.

In 1920, bishop Murray ordained Shoemaker a deacon in the Episcopal Church. Shoemaker then returned to his earlier post at Princeton through the school year, 1922–23. There, he maintained his ties with the Oxford Group; Buchman also made frequent visits to Princeton. However, by the time Shoemaker returned to Princeton, the movement's personal evangelism had begun to gather both friends and foes in England (where Buchman had started his "First Century Christian Fellowship" at Oxford and Cambridge) as well as America.

His wife, Helen Smith Shoemaker, whom he met at Princeton and married in 1925, was an author and Sculptor as well as fellow church leader. They had two daughters, one of whom married a missionary who served in Asia, and the other of whom also traveled extensively abroad as the wife of a State Department official.

In 1926, Shoemaker founded the 'Faith at Work' movement (later called LUMUNOS and Moral Re-Armament in the years immediately preceding World War II) out of his passion for personal witness in the workplace. Faith at Work begun circa 1926 in a mission at Calvary. On Thursday evenings through approximately 1936, lay persons both presented their witness of their life as Christians in the workaday world and were trained to witness to that world.

Bishop william T. Manning of New York approved of the Oxford Group and Shoemaker's taking the helm at Calvary Church in the Gramercy Park neighborhood. At Calvary, where he became rector after a successful two-year trial term, Shoemaker constantly balanced both the institutional and sacramental aspects of the church's life, as well as his personal faith as influenced by Buchman and the Oxford Group. He held outdoor services in nearby Madison Square beginning in the summer of 1927, attracting new parishioners through music as well as his sermons, and began transforming the church school that winter term.

However, when the Great Depression hit and continued, controversy grew around Shoemaker. In 1932, the Calvary vestry granted him an extended leave of absence to bring his ideas to a wider audience.

Around 1938, Faith at Work transformed into Moral Re-Armament. However, controversy grew because the latter dissociated from Christian churches and New Testament orientation. Moral Re-Armament also took an increasing share of Shoemaker's time and the facilities of Calvary House in New York. Shoemaker re-evaluated his priorities, including with Frank Buchman and the Oxford Group, as well as his commitment to evangelism, devotion to the Church of Christ in general and to the Episcopal Church. Efforts to work through these concerns in 1940 and 1941 proved fruitless. In the closing months of 1941, Calvary Church's vestry formally asked Moral Re Armament to stop using Calvary House.

Serious disagreements with Oxford Group founder Frank Buchman led Shoemaker to separate from Buchman in 1941. Sam Shoemaker and his followers later formed "Faith At Work" as a continuation of his interdenominational conference and publication projects.

This small group joined some others who were disenfranchised when the split came with MRA in 1942. They and many others met with Irving Harris whose work at the Calvary Evangel and later with its successors covered a period of over three decades. Irving gave structure to the Thursday evening services and was later the enabler of the Monday groups. These were to continue in one form or another until Faith at Work moved to Columbia, Maryland, in 1971.

The first week-end conference of Faith at Work, the progenitor of hundreds of such conferences to be conducted all over the country, in subsequent years was held at Calvary House in 1943. The means and methods adopted for the conference included:

Shoemaker had become involved in radio preaching, and in 1946, Dr. Frank Goodman of the Federal Council of Churches offered Shoemaker a daily five-minute spot on station WJZ. That proved successful, leading to a Sunday half hour broadcast on station WOR, and another half-hour program called "Faith in our Time".

Shoemaker's fame led him to receive a call (which he declined) to become Dean of San Francisco Cathedral in 1950. However, the following year, after celebrating his own quarter century of ministry at Calvary in New York, Calvary Church in Pittsburgh, Pennsylvania called Shoemaker to serve as its rector. The Bishop of Pittsburgh called to urge him to accept, as did a group of Pittsburgers who called themselves the 'Golf Club crowd'. He ultimately did, and in 1955 launched what he called the interdenominational 'Pittsburgh Experiment,' seeking to bring Christianity into everyday life, and about which he wrote The Experiment of Faith(1957). The Pittsburgh Jaycees named him their Man of the Year in 1956, and the previous year Newsweek named him among the country's ten best Preachers.

Although Bill Wilson later said in an address about Shoemaker at the St Louis AA convention in 1955 alongside Father Ed.

While based in Pittsburgh, Shoemaker continued to tape his sermons as the "Episcopal Hour" (and during 1957-1958 the "Art of Living") for distribution by the National Council of the Churches of Christ. Shoemaker also evangelized among young people and in the surrounding area, including setting up an Oxford Group meeting in Akron, Ohio. Shoemaker also had a half hour radio show called "Faith that Works." After the break with the Oxford Group in 1941 mentioned below, Faith at Work meetings also resumed.

Shoemaker also addressed an AA group in Charlotte, North Carolina, June 17, 1962 saying:

On November 7, 1963, an additional memorial Service was held in his honor at Calvary Church in Pittsburgh, and later yet another at Calvary Church in Manhattan, with Dr. Norman Vincent Peale contributing material for the commemorative edition of 'Faith at Work' magazine.

For the next eleven years, Sam and Helen Shoemaker managed to combine the diverse interests of Calvary Church with the life style and program of the Oxford Group. The church's ministry grew exponentially, by about 100 parishioners at the Sunday morning Service in his first year, and another 100 during the second. However, not all of Calvary's members could have been committed to the radical life style and "hot gospelling" of the Oxford Group. Selling some church lots on 22nd Street to build a new seven-story Calvary House in place of the old rectory also caused controversy.

Shoemaker wrote over thirty books, about half of which were circulating before A.A.’s 12 Steps were first published in the Big Book in 1939. Shoemaker's books were circulated in New York, Akron, and the Oxford Group.