He supported US participation in the First World War (later describing himself as a "gullible fool" in doing so[7]), and in 1917 volunteered as an Army chaplain, serving in France.

Clarence Edward Macartney of Arch Street Presbyterian Church in Philadelphia on July 13, 1922, with a sermon entitled "Shall Unbelief Win?".

The national convention of the General Assembly of the old Presbyterian Church in the USA in 1923 charged his local presbytery in New York to conduct an investigation into Fosdick's views.

His defense was conducted by a lay elder, John Foster Dulles (1888–1959, future Secretary of State under President Dwight D. Eisenhower in the 1950s), whose father was a well-known liberal Presbyterian seminary professor.

Fosdick escaped probable censure at a formal trial by the 1924 General Assembly by resigning from the First Presbyterian Church (historic "Old First") pulpit in 1924.

In ten stories of the 22-story belltower are classrooms for the religious and social training of the young[10]Fosdick outspokenly opposed racism and injustice.

His 1933 anti-war sermon, "The Unknown Soldier",[12][13] inspired the British priest Dick Sheppard to write a letter that ultimately led to the founding of the Peace Pledge Union.

Rockefeller funded the nationwide distribution of Shall the Fundamentalists Win?, although with a more cautious title, The New Knowledge and the Christian Faith.

He was the nephew of Charles Austin Fosdick, a popular author of adventure books for boys, who wrote under the pen name Harry Castlemon.