Kids should be studying the Constitution, & the Bill of Rights, critical thinking, research and math before they can go on to electives.
The line gets fine when it comes to beliefs. Philosophy and economics are examples of beliefs. Beliefs should be kept out of courses unless they compare all different types of similar related beliefs.
Comparison of religious beliefs of all types could be electives, but never required, courses. Practice of religious teachings, sexual practices do not belong in a curriculum.
My kids are 11 and 12 and I can’t believe how many of their assignments involve climate change, slavery, global warming, other cultures, native Americans. It is a full-time job to counter what the kids are “learning” in school.