Arthur Machen
Around 1890 Machen began to publish in literary magazines, writing stories influenced by the works of Robert Louis Stevenson, some of which used gothic or fantastic themes. This led to his first major success, "The Great God Pan". It was published in 1894 by John Lane in the noted Keynotes Series, which was part of the growing aesthetic movement of the time. Machen's story was widely denounced for its sexual and horrific content and consequently sold well, going into a second edition.
John Gresham Machen
After returning from Europe, Machen continued his work as a New Testament scholar at Princeton. During this period he gained a reputation as one of the few true scholars who was able to debate the growing prevalence of Modernist theology whilst maintaining an evangelical stance.
"The Origin of Paul's Religion" (1921) is perhaps Machen's best known scholarly work. This book was a successful attempt at critiquing the Modernist belief that Paul's religion was based mainly upon Greek philosophy and was entirely different from the religion of Jesus.
"Christianity and Liberalism" (1923) is another of Machen's books that critiqued theological modernism. The book compared conservative and Protestant Christianity to the rising popularity of Modernist (or "Liberal") theology. He concluded that "the chief modern rival of Christianity is Liberalism".
In "What is Faith?" (1925) he set before him the pastoral task of anchoring faith in the historical fact of Christ's atonement. He found liberal theology anti-intellectual, insofar as it spiritualized Christianity and treated it as merely an expression of individual experience, thus emptying the Bible and creeds of all definitive meaning.
These books, along with a number of others, placed Machen firmly in one theological camp within the Presbyterian Church. His work throughout the 1920s was divided between his time at Princeton and his political work with evangelical Presbyterians.
Despite his conservative theological beliefs, Machen was never able to fully embrace popularist fundamentalism either. His refusal to accept premillennialism and other aspects of Fundamentalist belief was based upon his belief that Reformed Theology was the most biblical form of Christian belief—a theology that was generally missing from Fundamentalism at the time. Moreover, Machen's scholarly work and ability to engage with modernist theology was at odds with Fundamentalism's anti-intellectual attitude.