William Ellery Channing was weary of having the epithet "Unitarian" flung at him in disdain. Ever since Henry Ware had been elected to the Hollis Professorship of Divinity at Harvard College, the temperature of public debate between orthodox and liberal factions of New England's Standing Order Churches had risen.
Many theological points were at issue. The turn to liberalism in New England churches had begun with the unitarian notion of the singular, or unitary, nature of God, antithetical to the trinitarian understanding of God as three: Father, Son, and Holy Spirit. But soon the debate widened. Was God a benevolent and loving presence that wanted the best for all humanity, or, as in Calvinist orthodoxy, a wrathful and exacting God? That debate called into question the orthodox idea of the elect, the notion that some are saved and others damned. Soon the orthodox/liberal controversy encompassed not only the nature of God, but also the nature of Jesus; was Jesus fully divine, or fully human, or partly each? Religious people debated the question of human nature—were humans good, and capable of distinguishing right and wrong, as the liberals believed; or, as in the orthodox view, were humans depraved, and captive to sin? And reason—where did that fit in? The orthodox insisted that the Bible alone was the valid basis for religious knowledge, while liberals maintained that the use of God-given reason and conscience was needed along with revelation. With Ware's election in 1805 to head Harvard College, the liberals had taken control of the seminary which was the primary training ground of New England's ministers. This caused great dismay among those of more orthodox beliefs.
By 1812, the young William Ellery Channing became the de facto leader of the Boston liberals following the untimely death of leading liberal Joseph Buckminster. Channing preached about a benevolent, loving God who had endowed humanity with innate goodness, rationality, and the wisdom to discern between good and evil. In a sermon delivered at the ordination of Jared Sparks in 1819 at the new liberal church in Baltimore, Maryland, Channing decided to snatch the label of Unitarian from those who would degrade it and to claim it proudly as his own. His address, "Unitarian Christianity," stands as a hallmark of Unitarian history. As David Parke writes:
The "Baltimore sermon" gave the Unitarians a platform and a spokesman. It placed them for the first time on the offensive in relation to the orthodox. It was very probably the most important Unitarian sermon ever preached anywhere.
In the hour-and-a-half-long address, Channing took on two tasks. First, he established reason as valid and necessary for the interpretation of scripture—not as the only basis for religious belief, but as an aid to revelation, for reading and understanding the meaning of the Bible.
Our leading principle in interpreting Scripture is this, that the Bible is a book written for men, in the language of men, and that its meaning is to be sought in the same manner as that of other books... With these views of the Bible, we feel it our bounden duty to exercise our reason upon it perpetually; to compare, to infer, to look beyond the letter to the spirit...
Having set the stage for biblical interpretation, Channing's second task was to lay out four reason-based conclusions of Unitarian Christians. He began with the unity of God, as opposed to the doctrine of the Trinity. Next, he postulated Christ as fully human, as opposed to having two natures, human and divine. Then he spoke of the moral perfection of God, which negated such doctrines as Original Sin and the eternal suffering of some while others were elected to salvation.
Channing's fourth point was about the purpose of Jesus' mission on earth. He rejected the idea that Jesus' death atoned for human sin, allowing God to forgive humanity. Channing admitted Unitarians differed on Jesus' role in human salvation. Some, he said, saw Jesus' life as a moral example. Others understood Jesus' death leading humans to repentance and virtue. Yet, he said, Unitarians did not consider Christ and his death as a blood atonement for human sin. Channing's fifth and final point was that Christian virtue had its foundation in the moral nature or conscience of humans, defined by love of God, love of Christ, and moral living.
Far from settling the simmering arguments, Channing's Baltimore Sermon brought them to a full boil. The Unitarian Controversy raged over the next quarter century. New England's churches continued to split along theological lines, and, within two decades of Channing's fateful sermon, one-quarter of Massachusetts' Standing Order churches became openly Unitarian. Other Unitarian leaders added defining voices to the movement, but Channing's Baltimore Sermon remains a key turning point in Unitarian Universalist history.