The line between public and private expression of religion requires balancing the constitutional guarantee of the free exercise of religion and the constitutional prohibition against the establishment of religion. Public schools, as government entities, and the teachers in them are allowed neither to inhibit the free exercise of religious expression nor to encourage it. This means that teachers may teach about religion but may not teach the religion itself. Students have a little more leeway in their religious expression because they are not official representatives of government. The author presents a 12-question test on religious instruction and expression designed to test teachers' knowledge about where the lines are drawn, and follows the questions with a discussion of the answers.