The Historical Roots of Separating Church and State

On June 26, 2026, the Religious Liberty Commission released its final report regarding the status of religious freedom in the United States. The commission declared that religious liberty in the nation is currently under significant attack. This body was established in May 2025 with a specific mission. Its primary goals were to identify emerging threats to religious liberty, uphold federal laws that protect citizen participation in a pluralistic democracy, and safeguard the free exercise of religion.

Despite these altruistic goals, the commission faced immediate criticism from its inception. Many observers argued that the composition and agenda of the group were biased toward a conservative Christian perspective. Over the course of a year, the commission conducted seven hearings. It heard testimony from approximately 100 witnesses.

The draft report recounts numerous incidents where individuals claimed they faced bias or mistreatment because of their religious faith. The report places the blame on government bureaucrats who allegedly show disdain for public demonstrations of religious conviction. A central argument in the report attributes much of this conflict to the use of the metaphor "wall of separation of church and state." The commission argues that critics use this phrase to justify excluding religious Americans from equal participation in the public square.

As the author of the book Separating Church and State: A History, I argue that the commission’s broadside against the concept of separating church and state is misplaced. However, this criticism is not new. Critics have portrayed the idea of separation as anti-religious and ahistorical ever since the Supreme Court embraced it in 1947.

In the landmark 1947 case of Everson vs. Board of Education, the Supreme Court addressed the issue of public financial aid for religious education. In this decision, the justices announced that they would use the concept of church-state separation as a guide for interpreting the religion clauses of the First Amendment to the Constitution. These clauses state that Congress shall make no law respecting an establishment of religion or prohibiting the free exercise thereof.

In the same decision, the justices employed the metaphor of a "wall of separation between church and state." This phrase was borrowed from an 1802 letter written by President Thomas Jefferson to an association of Baptist churches in Connecticut. At that time, the Baptists were a minority in a state that still maintained a religious establishment. Jefferson sympathized with their difficult position. He used the wall of separation metaphor to emphasize that religion is a matter that lies solely between man and his God. It is not a matter for the legislative powers of government.

The idea of having separate spheres for spiritual and secular functions and authority was advanced by both religious and secular thinkers. They believed this separation would benefit both religion and the state.

In his fifth-century work City of God, St. Augustine advanced the model of two entities. One entity was spiritual, and the other was temporal or earthly. Each entity had separate authority and functions. Augustine went so far as to use an image of two walled cities separated from each other. He used this image as a means to protect the purity of the church.

During the Protestant Reformation of the 16th century, both Martin Luther and John Calvin distinguished spiritual authority from earthly authority. They called for a clear division of labor between the two. Luther distinguished between two kingdoms: a spiritual kingdom and a temporal kingdom. These kingdoms had separate authority.

Similarly, Calvin wrote that Christ’s spiritual Kingdom and civil jurisdiction are things that are completely distinct. Because of this, he argued they must always be considered separately. He pointed out the great difference and unlikeness between ecclesiastical and civil power.

At the same time that religious reformers were discussing separation, they were employing concepts of walls, hedges, or other barriers. They wanted to ensure that secular and religious realms remained apart.

Protestant Anabaptists, including groups such as the Mennonites, Hutterites, and Brethren, took the theological idea of separationism to heart. They sought to keep their communities apart from what they saw as the corruptions of the fallen world. These groups declined to swear oaths of allegiance to civil authorities. They also avoided otherwise participating in civic functions.

The early leader of the Mennonites, Menno Simons, used the term "separating wall" to illustrate the degree of separateness their faith required from civil authority.

Finally, Roger Williams, the Puritan-turned-Baptist founder of Rhode Island, advocated for complete religious liberty. He called for maintaining a hedge or wall of separation between the garden of the church and the wilderness of the world.

Enlightenment figures, such as John Locke, also advanced notions of the separation of church and state. In 1689, Locke wrote that the church must be absolutely separate and distinct from the commonwealth and civil affairs. He stated that the boundaries on both sides are fixed and immovable.

Influential British writer James Burgh called for building an impenetrable wall of separation between things sacred and civil. He argued that the less the church and state had to do with one another, the better it would be for both. Scholars believe that Burgh’s writing was likely one source for Jefferson’s famous 1802 letter to the Connecticut Baptists, where he used the same metaphor.

Thus, members of America’s founding generation were familiar with the concept of distinct spheres of authority between religion and government. They understood the necessity of keeping those functions separate.

Even though Jefferson used the wall metaphor only once, he worked assiduously throughout his life to advance religious freedom via church-state separation. James Madison employed similar imagery. He called for a great barrier between the two spheres.

Church-state separation was not just an imagery idea. It was a concept that many people embraced. As Madison wrote, religion and government will both exist in greater purity the less they are mixed together.

As a result, to this day, many denominations and religiously affiliated groups support the separation of church and state. Groups such as many Baptists, Seventh-day Adventists, and members of Reform Judaism view this separation as essential for maintaining religious freedom.

And church-state separation continues to receive popular support. According to the Pew Research Center, in 2026, 54% of Americans say the government should enforce church-state separation. This is a consistent percentage. In contrast, only 13% believe it should stop enforcing it. This figure is down from 19% in 2021.

Despite this long pedigree, the Religious Liberty Commission’s report expresses particular disdain for the wall metaphor. It states that the phrase does not appear in the First Amendment or anywhere else in the Constitution. The report calls it a belabored metaphor. It argues that the phrase can wrongly imply that church and state are opposed to one another and must remain completely separate.

The report also takes a narrow view of what is prohibited by the religion clauses. It states that the government may not officially prefer one religion over another, take over the functions of a church, or coerce religious observance. This narrow interpretation would otherwise allow for other types of church-state intermixing. For example, it would permit government funding of religious education.

In her final opinion as a Supreme Court justice in 2005, Sandra Day O’Connor reflected on the importance of church-state separation. As a judicial conservative, she emphasized that this separation is crucial to guaranteeing full religious freedom.

She noted that the First Amendment expresses the Nation’s fundamental commitment to religious liberty. It does so by means of two provisions. One protects the free exercise of religion. The other bars the establishment of religion.

She concluded with a challenge to those who would change the current system. She asked why we would trade a system that has served us so well for one that has served others so poorly.

That the commission’s report ignores the benefit of church-state separation to American society is troubling.