A teacher may not keep a personal Bible or other religious material on her desk if they are not being used as part of an objective and neutral academic curriculum. The teacher may also be prohibited from reading a Bible during free reading times in the classroom while students are present. Courts have ruled that a teacher would violate the Establishment Clause by this overt expression of a particular religion. However, the teacher could keep a personal Bible in her desk drawer or in some other location out of sight of the students and could read the Bible during times when students are not present in the classroom.
Teachers may not keep Bibles in a classroom library unless the Bibles are included with other religious texts (such as the Koran) as a small part of a general classroom library the students may consult for academic purposes. Similarly, a teacher should not display religious material in the classroom unless it is directly related to the curriculum and is not either devotional or proselytizing in nature.
—Keeping Christ in America’s Public Schools, Gibbs & Gibbs, 2008