It provided some of the foundations of America's laws and is referenced in literature from Dante to Dostoevsky. Bring it into the public schools, though, and the Bible can be problematic.
When parents in Frankenmuth, Mich., proposed a high school class about the Bible a year ago, the superintendent's first question was a natural one: Is it legal?
The group providing the curriculum said yes: The course was elective, treated the Bible as literature and history, and complied with a 1963 US Supreme Court ruling that said schools could teach about religion in a secular way.
The ACLU and People for the American Way said no: The curriculum in question promoted a specific Christian interpretation and looked at the Bible as a source of history, both things that crossed over a line into unacceptable territory.
"We talked to six different lawyers, and heard six different things," says Mike Murphy, superintendent of the Frankenmuth School District.
In the end - after a year of high interest and emotion on the part of some parents - Mr. Murphy recommended against the course and the school board seconded his decision earlier this month. His thinking, he says, was based not just on fear of a lawsuit, but on concerns that the class, as proposed, seemed simplistic. Besides, the school's social studies and English classes already taught religion's place in history and literature.
"It wasn't a vote against the Bible, it was a vote against this particular curriculum," says Murphy.
When it comes to religion, there's an odd patchwork of what's allowed and banned in schools around the country, and the questions raised in the Frankenmuth controversy are complex: Does separating church and state mean omitting religion from public schools entirely? If it is permissible to teach about religion, where is the line separating academics from indoctrination? Can young students understand the subtleties of faith versus intellectual inquiry in the same way adults or teenagers can? And even if a curriculum seems fine, what ensures that teachers won't proselytize?
"If we leave religion out completely, we cheat our students out of a good education, and we don't prepare them to live in a world in which religion is very important," says Charles Haynes, a senior scholar at the First Amendment Center at the Freedom Forum in Arlington, Va. "The question is, how do we do it properly?"
After periods in which religion was first a foundation of public schools, and then excluded entirely, the pendulum has started to swing to a middle ground, says Mr. Haynes.
He's worked to help craft guidelines acceptable to all. The key - whether the course is comparative religions or the Bible - is keeping scholarship at the heart of the curriculum, not favoring any one faith, and recognizing the difference between sacred history and actual history, he says.
"We have more consensus today than we've ever had on how to deal with religion in the public schools," says Haynes.
"The bad news is that carrying out that consensus is difficult given the long history [of controversy]."
Passionate views on both sides fuel disagreements, and the media often fan the flames. In one recent high-profile case, headlines proclaimed that the Cupertino Union School District in California had banned the Declaration of Independence because of religious references.
The fact that the Declaration of Independence hangs on a wall of the school library, is part of the curriculum, and is present in history textbooks hasn't stopped vitriolic e-mails and phone calls from pouring in.
"We were completely caught off-guard with that headline," says Jeremy Nishihara, a district spokesman.
The district is facing a lawsuit from fifth-grade teacher Stephen Williams that alleges he was discriminated against when his principal vetoed some of his supplementary history materials, including religious writings by former American leaders and three paragraphs of the Declaration.
The district won't comment on the lawsuit, but some parents had reportedly complained that their children felt uncomfortable in the class.
If the case shows that historical documents were chosen selectively by the teacher, it may be "an example of how these guidelines that say we can teach about religion can be used to push an agenda," says Haynes. "Not many teachers do have an agenda, but enough do that these fights can tear communities apart."
Courts often rely on the so-called "Lemon" test to decide matters of religion in the schools, says Perry Zirkel, a professor of education and law at Lehigh University. Named for a 1971 decision, Lemon v. Kurtzman, the test involves a three-pronged guideline: whether the activity has a religious purpose, whether it has an effect that promotes or inhibits religion, and whether it encourages "excessive entanglement" between public and religious institutions.
Later this spring, for instance, the Supreme Court will consider whether public schools can post the Ten Commandments - a decision that could hinge, in the end, on whether the effect of the display is deemed to be religious.
Still, even court rulings that use the Lemon test as a guide are frequently inconsistent, says Professor Zirkel. "Judges, like the rest of us when you take an emotional issue like religion, often decide based on their heart and then use things to justify it," he says. "The two toughest issues in school litigation are religion and race, and it's almost impossible to be truly rational about either one given how we're brought up in society."
When it comes to teaching about the Bible, there's less court guidance, although some approaches have been deemed too religious and struck down. The National Council on Bible Curriculum in Public Schools, which created the class proposed in Frankenmuth, insists its approach complies with all the guidelines, and says it's being used in 290 school districts in 35 states.
"There's no indoctrination. We do not refer to it as the truth. We just refer to, 'this is what the Bible says,' and students draw their own conclusions," says Elizabeth Ridenour, president of the council.
Not everyone agrees with her assessment. The council's curriculum has been the subject of controversy, with some calling it a form of indirect proselytizing.
"They talk about [the Bible] as history," says Elliot Mincberg, legal director at People for the American Way. "It's a matter of religious faith whether you believe what's in the Bible or how literally you believe it."
In the end, though, Mr. Mincberg, like Haynes, believes that consensus is possible. "Any individual is free to practice [his religion], but the government shouldn't come down on anyone's side," he says. "I think if you keep in mind that vision, the conflicts can often be worked through."