As a matter of fact, I absolutely do think that religion should be taught in school.

Seriously.

All schools should teach to teach a mandatory class (lasting at least a semester) on comparative religions and mythologies. Religion would have to taught first from a historical perspective, from origin myths of classic religions (Greek, Roman, Norse, etc) to the rise of the dominant faiths. 

Later in the course, students must gain a working understanding of what each major religion believes, and how those beliefs compare to the other major religions.

And yes, I did say mandatory, for all schools public or private.