Prerequisites
If students must have certain basic courses, plus one elective ("Intro to Criticism"?), before being permitted to enroll in "The Bible as Literature", then the earliest a student could take the course is at 16 years old. That ought to be plenty old enough to form an independent opinion.
At 18, they can vote. At 18, they can enroll in the military and go die for their country. At 18, they can marry. At 16, they ought to be able to study something serious that might be controversial.
Education is about learning to think. If a kid wants to use high school as something more than a vocational school, should they not be able to do that? Should they not at least have the opportunity to choose?