The United States Supreme Court has held that neither students nor teachers shed their constitutional rights (including their free speech and free exercise rights) at the schoolhouse door. However, as applied to school staff and teachers, courts have only upheld these rights in public schools with respect to other school personnel, not to teacher communications with students. Just as in other government workplaces, the school may control a teacher’s speech in front of students (who are the “customers” or “clients” of the government’s education business). Courts have determined that Establishment Clause considerations generally trump a teacher’s free speech and free exercise rights when the two conflict. Since the teacher is an agent of the government while on school property, anything the teacher says concerning religion can be attributed to the government and can become an unconstitutional establishment of religion.
When teachers communicate with other employees, they enjoy all the free exercise rights of other government employees as controlled by the legal principles described in the Religious Guidelines for Federal Employees. [Highlight Religious Guidelines for Federal Employees and make a hyperlink with content at end of all this. What is the link?]
—Keeping Christ in America’s Public Schools, Gibbs & Gibbs, 2008