Oklahoma’s top education official said Thursday that schools will be required to teach the Bible in all classrooms and keep a copy of it on hand.

Oklahoma schools must incorporate the Bible into their curricula for grades 5-12, according to a memo sent by Superintendent of Public Instruction Ryan Walters to all school districts. The schools are told to use the Bible and Ten Commandments to show their “substantial impact on our nation’s founding fathers and foundational principles in our Constitution.”

The memo stated that “immediate and strict compliance” is required.

Walters stated at a meeting of the Oklahoma State Board of Education on Thursday that “We will be teaching the Bible in classrooms to ensure this historical understanding for all students in Oklahoma.”

Americans United for Separation of Church and State is a civil liberties nonprofit group that said in a press release that Walters’ new Bible policy “tramples the religious freedom of children and families attending public schools.”

In a statement, Rachel Laser, CEO of the group, stated that “this is textbook Christian Nationalism. Walters abuses his power to force his religious beliefs onto everyone else’s kids.” She wrote that her organization was “ready to take action,” but she did not promise legal action. The group has already filed a lawsuit to stop a Louisiana law that requires the Ten Commandments be displayed in public school.

Walters, an ex-high school history teacher who was elected to the state legislature in 2010, has gained national recognition as a strong advocate for integrating Christian teachings and beliefs into education policy.

Gov. Kevin Stitt (a Republican) recently approved a set of regulations proposed by Walters, which included prayer time in schools, and expanded the “foundational value” of the Education Department to include a Creator and acknowledge the existence of both good and evil.

Walters, too, has drawn criticism. Stitt issued a directive this month that prohibits state agencies from signing sole-source contracts for marketing and public relation firms. Walters had hired a $200/hour public relations firm to help him gain national media attention.

This week, the state Supreme Court ruled that a contract between the state and a Catholic Charter School violated state and federal laws and had to be canceled. This would have been the first religious charter schools in the United States.

In a press release, Walters referred to the ruling as “sanctioned racism against Christians”. He wrote: “This ruling can and must not be upheld.”

The State Attorney General Gentner drummond, a conservative Republican himself, was not in agreement.

He said that the decision was a huge victory for religious freedom. “The framers and drafters of Oklahoma’s Constitution understood that the best way to protect religious liberty was by prohibiting the state from sponsoring any faith at all.”