During its opening week of the term, the U.S. Supreme Court will hear oral argument in what some deem the most important religious liberty case in decades — Hosanna-Tabor Evangelical Church and School v. Equal Employment Opportunity Commission.

The case involves a constitutional First Amendment doctrine known as the "ministerial exception," which the court is addressing for the first time.

The doctrine, upheld by lower courts for four decades, protects religious organizations by exempting them from certain employment rules (anti-discrimination laws) relating to their "ministerial employees." The doctrine reflects the long-standing recognition of church autonomy in hiring and firing ministers without government interference.

This freedom enables the church to define and control its leadership, beliefs, character and message. The question the Supreme Court will consider is who counts as a "ministerial employee" and thus whose employment status is within the sphere of the church's autonomy.

Hosanna-Tabor Evangelical School is a small, church-run evangelical Lutheran school in suburban Detroit. Its former fourth grade teacher — Cheryl Perich — was hired to teach an academic curriculum. But she was also hired to teach her students religion classes, lead class prayer, lead scriptural devotionals, attend school-wide chapel services with her class, infuse religion into the secular subjects she taught and be a good Christian role model to her students. In short, her job was to instill the Lutheran faith in the next generation in her classroom.

During one summer recess, Perich fell ill and took an extended leave of absence. After seeking to accommodate her absence, the church eventually had to hire a replacement.

A number of Christian denominations — including the Lutheran Church — have long taught that Christians should resolve religious-related disputes within the church, rather than sue each other in secular, civil courts. This teaching comes directly from the Bible (1st Corinthians, chapter 6).

To obey this scriptural command, the Lutheran church operates an elaborate internal system for resolving religious employment disputes, among others, and members are obligated to address such disputes in that forum.

So when Perich threatened to take the church to court instead, she did so contrary to church teaching. The church released Perich from her call as a commissioned minister and teacher for insubordination and disruptive conduct in violation of church teachings.

Perich claims the school retaliated against her for filing a discrimination claim with the government, the Equal Employment Opportunity Commission (EEOC). She wants the courts to reinstate her as a teacher at the school over the objections of the church that runs the school. The Church argues her lawsuit cannot proceed because she was a "ministerial employee." Her defiance of the church's belief in resolving religious disputes internally justified firing her.

The trial court ruled in the church's favor, but the appeals court sided with Perich, reasoning that she did not teach enough religion amid the secular subjects during the school day to be deemed a minister.

This case is not just about firing a teacher in a religious elementary school. It concerns a much broader principle: the right of religious institutions to control their own affairs.

The Supreme Court long ago recognized that government may not tell churches whom to choose as their clergy, or how to transfer power from one leader to another, or whether to reinstate a religious leader who has been found unfit by the church. Courts may not reverse decisions made by religious tribunals or choose sides in a religious controversy. And the Supreme Court has been right.

If the First Amendment means anything, it means that the government is entirely incompetent to decide matters of religious faith, doctrine and practice.

Indeed, if the "ministerial exception" did not exist, the landscape of religious life in our country would likely be vastly different. Because of the constitutional protection afforded by the "ministerial exception," churches can lawfully select leaders and the authorized bearers of its message based on their sincerely held religious beliefs.

Catholics and Orthodox Jews can have an all-male clergy. Jews, Muslims and Hindus can base leadership decisions on ethnicity and descent. And where marital-status discrimination is prohibited, churches can "discriminate" based on celibacy.

If, as the EEOC urges, the Supreme Court decides the ministerial exception should not exist at all, the floodgates open for lawsuits claiming all sorts of "discrimination" by religious institutions that heretofore had been accepted as a legitimate form of religious expression.

More likely, the Supreme Court will recognize the danger of eliminating that exception and will uphold the doctrine as grounded in our constitutional history and applicable to the teacher in this case. Whatever the outcome, the decision will likely have a significant impact on the level of autonomy of many religious institutions in this country.

Hannah C. Smith twice clerked at the U.S. Supreme Court and is a member of the Deseret News Editorial Advisory Board. She is senior counsel at The Becket Fund for Religious Liberty, a public interest law firm that defends religious liberty for people of all faiths. The Becket Fund is co-counsel at the Supreme Court for the Hosanna-Tabor case.