I took a Comparative Civilizations class in grade 12 (basically an Advanced Placement Social Studies class) which included some study of Christianity, Islam and Buddhism but from a historical and contextual angle (basically, "these are these religion's basic key beliefs, where they historically gained traction, and when and where some of the more notable subgroups of them came into play), not a theological one. I'm in full support of religion being taught in public schools in that fashion, but theology and indoctrination can definitely stay away.