The Freedom From Religion Foundation (FFRF) is protesting a ceremony where the newly formed U.S. Space Force designated and blessed its own bible.

Selecting one book as the official “holy book” of a governmental branch is improper and an egregious violation of the Establishment Clause, which prohibits government speech or action endorsing religion, FFRF emphasizes in its letter to the Pentagon.

High-ranking service members attended the function, which used this language: “May this Bible guard and guide all those who purpose that the final frontier be a place where God will triumph over evil, where love will triumph over hate, and where life will triumph over death.” The Museum of the Bible, which has been heavily criticized for transparent proselytizing and poor history and scholarship, donated the bible.

“The oath that Space Force commanders will take is a solemn promise to defend not the bible but our Constitution, with their lives if necessary,” FFRF Co-Presidents Dan Barker and Annie Laurie Gaylor write to Defense Secretary Mark Esper and Gen. John W. Raymond, first chief of Space Operations. “That Constitution, which founded this great nation, is a godless document whose only references to religion are exclusionary, such as Article VI promising ‘no religious test shall ever be required’ for public office.”

Like the Constitution itself, the only oath provided for in the Constitution is godless. The presidential oath in Article II does not include the words “So help me God." Nor is there any mention in the Constitution of placing a hand on a bible. Most service members do not actually use a bible when swearing their oath, and they’re in good company: Theodore Roosevelt, Franklin Pierce, and John Quincy Adams took their presidential oaths without a religious text.

The Space Force has reportedly selected and singled out not just the Christian bible, but a Protestant version: the King James Bible. The decision to select and honor one particular religion’s holy book in this manner excludes and diminishes the citizenship of every nonreligious service member, in addition to adherents of other faiths. More than one-quarter of all Americans are religiously unaffiliated and another 6 percent are non-Christians practicing a minority religion. Almost one-fourth of military personnel identified as atheist, agnostic or nonreligious in a survey conducted eight years ago.

It is impermissible for this new branch of the U.S. military to clearly express favoritism for one particular holy book over every other or over nonreligion, FFRF concludes.

The Freedom From Religion Foundation is a national nonprofit organization with more than 30,000 members across the country who object to entangling religion with government. One-quarter of its members are active-duty military or veterans. FFRF works to protect the constitutional separation between state and church, and to educate about nontheism.