WASHINGTON -- Employees of religious organizations whose job duties reflect "a role in conveying the Church's message and carrying out its mission" are barred by the First Amendment from suing over employment discrimination, said the Supreme Court in a unanimous opinion handed down Wednesday morning.

The decision in Hosanna-Tabor Evangelical Lutheran Church and School v. Equal Employment Opportunity Commission was the first time the Supreme Court had endorsed the "ministerial exception" to discrimination protections that many courts of appeals have come to recognize over the past several decades.

"Requiring a church to accept or retain an unwanted minister, or punishing a church for failing to do so, intrudes upon more than a mere employment decision," wrote Chief Justice John Roberts on behalf of the entire Court. "By imposing an unwanted minister, the state infringes the Free Exercise Clause, which protects a religious group's right to shape its own faith and mission through its appointments."

Paul Horwitz, a constitutional law professor at the University of Alabama and and author of "The Agnostic Age: Law, Religion, and the Constitution," told HuffPost that the Court's decision backed up the central constitutional principle that "the church cannot administer the state, and the state cannot administer churches."

The unwanted minister in this case was Cheryl Perich, a "called" -- or ordained -- teacher at Hosanna-Tabor, a Michigan church and grade school that is part of the Lutheran Church-Missouri Synod. In 2004, she went on disability leave for what was soon diagnosed as narcolepsy. Per its policy, the school asked her to resign once her absence exceeded six months, but she refused. Rather than submit to the school's request that her complaint be handled according to the church's tenet of internal dispute resolution, Perich threatened to file a complaint with the EEOC under the Americans with Disabilities Act. In response, the Hosanna-Tabor congregation rescinded Perich's call, which drove her to follow through on her EEOC threat.

Perich disputed Hosanna-Tabor's claim that she was subject to the ministerial exception, arguing that she mainly taught secular subjects and that the synod's preference to settle its disputes internally hardly rose to the level of church doctrine.

Conceding its reluctance to "adopt a rigid formula for deciding when an employee qualifies as a minister," the Supreme Court went on to reject Perich's argument based on the overall context of her employment. Perich, the Court noted, underwent intensive religious training in order to receive her call. As a teacher, she conducted religion classes four times a week, led her classes in prayer three times a week and took her students to chapel services once a week. That those duties took up only a small portion of her time was immaterial to the justices.

"The issue before us," wrote Roberts, "is not one that can be resolved by a stopwatch. The amount of time an employee spends on particular activities is relevant in assessing that employee's status, but that factor cannot be considered in isolation, without regard to the nature of the religious functions performed."

Although unanimous, Roberts' opinion did come supplemented by a couple of concurrences that were in slight tension with one another. Justice Clarence Thomas, writing for himself, said that the First Amendment requires civil courts "to defer to a religious organization's good-faith understanding of who qualifies as its minister," regardless of the employee's actual work duties.

Justice Samuel Alito, joined by Justice Elena Kagan, took the opposite approach, attempting to define what a minister is. The ministerial exception, Alito wrote, should apply to any person "who leads a religious organization, conducts worship services or important religious ceremonies or rituals, or serves as a messenger or teacher of its faith."

The concurrences touch upon a fault line that some of the justices exposed during the case's oral argument last year: To what extent can religious organizations shield themselves from employment laws by simply deeming all of their employees to be ministers?

This time, the other justices seemed satisfied by their chief's language pointing to "the formal title given Perich by the Church, the substance reflected in that title, her own use of that title, and the important religious functions she performed for the Church," leading them to conclude that "Perich was a minister covered by the ministerial exception."

That holistic assessment, said professor Sally Gordon of the University of Pennsylvania Law School, "left open enough wiggle room" for lower courts to refuse to apply the ministerial exception where an ordination is blatantly fraudulent or a mere pretext.

