In American evangelical politics, the old adage that “the enemy of my enemy is my friend” has proven true time and again. Deists and Baptists, for example, united against Congregationalists and Episcopalians in the early republic for the cause of religious freedom. Today, pro-life Catholics and evangelicals lay aside their theological differences to defend the sanctity of the womb. In the Scriptures, the Apostle Paul asked the Corinthian church, “what fellowship has light with darkness?” (2 Cor. 6:14) Politically speaking, they’ve had much in common in America.
Theologically, high church Unitarians and Trinitarian evangelicals appear like oil and water. William Ellery Channing, the so-called father of American Unitarianism, once called the Trinity “the most unintelligible” doctrine that had ever been disputed among Christians. However, to evangelicals, Unitarians were not “Christian” in even the most basic sense. By rejecting the tri-unity of God, Unitarians challenged the most foundational doctrine in the history of the church ever since the Council of Nicaea (325 AD) declared that the Father and Son were “the same essence” (homoousios). Nevertheless, evangelicals and Unitarians occasionally lowered their swords in order to help one another in their various pursuits.
For instance, in 1840, Harvard Unitarian Andrews Norton actually reprinted two articles from the conservative Presbyterian periodical The Biblical Repertory and Princeton Review, edited by Charles Hodge, in order to discredit the Transcendentalists, a group of young idealists within Unitarianism that Norton (and Hodge) found to be irrational and overly influenced by German theology. Ironically, it was the most liberal Christians of the day who sometimes appealed to conservatives to critique those farther left than themselves. Conversely, evangelicals sometimes appealed to Unitarians to argue against their fellow evangelicals. On more than one occasion, Baptist Isaac Backus appealed to proto-Unitarian rationalist Charles Chauncy in his critique of the Puritan Halfway Covenant and in his defense of immersion.
The tenuous relationship between Unitarians and Baptists, however, was much more political than theological. And it wasn’t always one-sided. For example, when Isaac Backus’s Baptist delegation appealed to the First Continental Congress for religious freedom, two out of the three men who dismissed them were Unitarians: John Adams and Robert Treat Paine (the third was Samuel Adams, a Calvinistic Congregationalist). The Unitarian elite were heretics in the eyes of their evangelical brethren, but they were stalwarts of the Standing Order. In other words, they stood in favor of the union between church and state, at least in New England. They were theological liberals but social conservatives. On the other hand, remarkably enough, Baptists were often fond of Unitarian leaders and vice versa. For example, the Baptist church in Haverhill, Massachusetts, pastored by Hezekiah Smith, was largely made up of Federalists and supportive of President John Adams. Although they led the opposition to an approval in Haverhill of the Massachusetts constitution in 1780 which upheld religious establishment, a measure which Unitarians supported, they supported Adams’s foreign policy toward France and his friendliness to religion. In Boston, John Adams and John Hancock, both Unitarians, would occasionally come to hear Samuel Stillman preach at First Baptist Church.
Unitarians also supported Baptist activism in various ways. In 1829, when Baptists and Presbyterians campaigned to outlaw Sunday mail delivery (a position opposed by others as a union of church and state), the Christian Register, a Unitarian periodical, advocated the cause alongside evangelicals. Unitarians even helped Baptists to do something they had strived for decades to accomplish: disestablish religion in New England. By receiving tax dollars from the state to support their Congregationalist churches (not until 1825 did Unitarians break away and become a new demonination), Unitarians forced orthodox Congregationalists to rethink the validity of the entire ecclesiastical tax system and to question whether or not it was indeed supporting the cause of religion. The state church that Trinitarians had long argued was for the “public good” had now become an engine for heresy, leading many to see the Baptist case for religious freedom in a whole new way. Baptists and Unitarians, though theologically worlds apart, were not always on opposing sides in the new American nation. As the saying goes, the enemy of my enemy.