The problem is that there are such divergent views in the world. From which perspective should a course be taught? IMO, religion, philosophy spirituality and ethics need to be modeled at home, and possibly at a private, religious after school program chosen by parents.
College is time enough for young people to learn about theology in the classroom.
What is the elementry or secondary school teacher supposed to do when they get to the point where current science has no answers? Wht do they tell the child that asks "What was there BEFORE the Big Bang?"? Do they lie to the students and say that there is only one theory in existance?
What do they tell the child that asks about the relevance of Gallieo and why his ideas were fought against? How are the time periods of the Crusades, the Spanish Inquistion and the Reformation explained? Should all of these items be stricken from public schools because they involve religion in an explanation?
It seems the zeal to strike religion from public view exceeds common sense when we get to the point where we can't teach significant portions of science or history because it might involve mentioning religion.