If you could take the politics, indoctrination, and obvious desire to "own the Libs" out of it, I think it's fine for children to learn about how decisive Christianity was to the development and trajectory of western civilization. I am infinitely better informed about the history, literature, and art of western civilization because I understand the role of Christianity.
Keeping a hard copy of the bible in the classroom is preposterous. It's intent is to "own the Libs".
You can't appreciate Dante, Shakespeare, Harriet Beecher Stowe, or Martin Luther King Jr. without any knowledge the influence of Christianity.
That would have to be finessed though, so it passes constitutional muster and does not negate other faith traditions. .