What role should religion play in the American public school classroom? My own knee-jerk response would be, “none whatsoever,” but the Constitution isn’t quite so direct on the subject. And, because this is America, there’s an organization out there ready-made to exploit that murkiness.

A fascinating Washington Post story looks at the Christian Educators Association International, which since 1953 has guided “teachers of faith” on how to express that faith legally in the classroom. The goal of the organization—which is the only nonteacher plaintiff in the Friedrichs v. California Teachers Association case now before the Supreme Court—is “to bring the light of Jesus Christ into public school classrooms across the country” by educating likeminded teachers on what they can and can’t teach, according to the Post article:

The Christian Educators Association International, an organization that sees the nation’s public schools as “the largest single mission field in America,” aims to show Christian teachers how to live their faith—and evangelize in public schools—without running afoul of the Constitution’s prohibition on the government establishing or promoting any particular religion.

“We’re not talking about proselytizing. That would be illegal,” said [Finn] Laursen, the group’s executive director. “But we’re saying you can do a lot of things. … It’s a mission field that you fish in differently.”

So what exactly does this different type of fishing look like? The Post article goes into detail: You can leave a Bible on your desk, or a cross dangling from your filing cabinet, and discuss your own personal beliefs with students. You can pray in the teachers lounge, or during before- or after-school activities, and “witness for Jesus by acting in a godly manner,” and inspire by example. But even as you exercise your own right to free speech, as a government employee, you cannot force your beliefs on your students during class.

The Center for Public Education lists several examples illustrating the “tightrope” teachers must walk when it comes to religion:

OK: Teaching about the Bible, the Torah, or other sacred texts and their influence on human behavior. No one denies that religion has strongly motivated behavior in the United States and around the world. Acknowledging that fact in the curriculum does not raise First Amendment concerns.

Wrong: Teaching sacred documents with devotion or as singular truth. It crosses the line when a teacher or school district portrays one religion or religion in general as the preferred belief.

Like most forms of evangelical Christianity, the Christian Educators Association International (motto: “Onward Christian Teachers“)—which has positioned itself as an alternative to traditional teachers unions, thus its role in the Friedrichs suit objecting to forced union dues—is flourishing. The membership roster has between 6,000 and 7,000 members: “We have teachers in every state and at military bases,” Finn Laursen, the organization’s executive director, told me. And the organization runs weekend trainings to help teachers “rekindle their passion, calling and courage to transform their schools with God’s love and truth” several times a year.

In middle school, I had a teacher who regularly reminded students of the Monday night Young Life meetings he sponsored; on Tuesdays, he’d spend the first few minutes of class palling around with the chosen ones about all the fun and fellowship they’d experienced together. This was private school, so he was well within his rights, but those of us who weren’t Christian, or weren’t his brand of Christian, were automatically excluded from his fun fraternity.

But even as an impressionable seventh-grader, I didn’t for an instant long to join his club; I just longed for the man at the front of the classroom to get on with the job—teaching—he was being paid to do.