Information drawn from sources including:
Channing, William Henry, Memoir of William Ellery Channing with Extracts His Correspondents and Manuscripts, In Three Volumes, (Boston, 1851)
Wright, Conrad, Three Prophets of Religious Liberalism: Channing, Emerson, Parker (Boston: Skinner House, 1984).
Channing has been called the single most important figure in the history of American Unitarianism. His 1819 sermon, "Unitarian Christianity," gave "the liberal Christians of his day a party platform," [Wright, Three Prophets of Religious Liberalism: Channing, Emerson, Parker]. He publicly affirmed what liberal Christians had been saying privately: He rejected Trinitarian dogma that made Christ equal to God and Calvinist creeds that demeaned the inherent worth and dignity of human nature, effectively bringing Unitarianism out of the closet. Thanks in no small part to Channing, liberal Christians no longer hid their objections to an orthodox Christianity and Unitarianism emerged as a new religious tradition.
Channing preached, lectured, and wrote texts that insisted that God takes pleasure in making human beings happy and finds joy in encouraging the infinite progression of human beings toward the moral perfection of their souls. He set aside the Calvinist image of God as wrathful, angry, and punitive and rejected the portrayal of humans as irrevocably fallen, broken, and sinful.
William Ellery Channing was born into a family of the Newton, Rhode Island elite. His maternal grandfather was a signer of the U.S. Constitution and his father, who was the District Attorney for Rhode Island, entertained in his home such men as George Washington and John Jay, another signer of the Constitution.
Harvard-educated, Channing brought together in his theological projects the Enlightenment God of Reason, the Biblical God of Christian Scriptures, the God of Piety known through a spiritual change of heart, and the God of Providence who acted through business and government affairs to enhance human life on earth. In this way, Channing was the culmination of the American Enlightenment and at the same time the transition point to a liberal faith that would eventually remove belief in God, the Bible, Christianity, or Christ as a requirement for Unitarian faith.
Human improvement, for Channing, was a divine mandate. Thanks in no small part to Channing, the affirmation of the worth and dignity of human nature became foundational for Unitarian faith. Human nature was now viewed as essentially sacred, perfectible, and moral. Channing's essays, sermons, and discourses during the 19th century sold more than 100,000 copies in Europe and America. He gave the middle class a religion that affirmed what they personally experienced: progress, liberty, and the pursuit of happiness as a rational, sacred, and political right.
According to Channing, "The true happiness of man has its seat in the mind which God has breathed into us, in the enlargement of its powers, in the elevation of its sentiments, in the firmness and purity of its principles, in its ascent to its native heaven." Moreover, Channing believed that the religion he preached could help bring about "a moral renovation of the world." And as the years wore on, he expected "less and less from revolutions, political changes, violent struggles... from any outward modification of society. Corrupt institutions," Channing insisted, "will be succeeded by others equally, if not more, corrupt, whilst the root principle lives in the heart of individuals and nations; and the only remedy is to be found in a moral change, to which Christianity, and the Divine power that accomplishes it, are alone adequate."