Understanding the roles that the many different forms of religious belief have played in human history is, I think, worthwhile to study. Unless you assume that religion is something more than a cultural phenomenon, there is no reason that all its many forms, implications, and preachments should not be laid open for all to see.
However, most religious people want to have their cake and eat it too, i.e. they want a particular brand of culture and belief to be given an understood preference in the classroom.
Oh, by the way, nothing is taught in any church, christian or otherwise, things are simple asserted.
