They were soon published in four volumes entitled The Battle Over the Bible, Evolution versus Creation, The Virgin Birth—Fact or Fiction?

[1][2] In 1925 he was adviser on the Bible to Clarence Darrow in his defense of John Thomas Scopes, a schoolteacher who was charged with teaching evolution in his classes.

In 1927 Potter returned to the ministry at the Church of the Divine Paternity, a Universalist congregation on Manhattan's Upper West Side.

In 1929, his progressive ideas led him to resign his post and found the First Humanist Society of New York, whose advisory board included Julian Huxley, John Dewey, Albert Einstein, and Thomas Mann.

"[4] Potter became a vocal advocate for social reform, campaigning vigorously against capital punishment, promoting "civil divorce laws," and supporting birth control and women's rights.