As a Religious Studies major, I'm learning a lot about how "religions" come about - what lead to the beginnings of Lutheranism, for example ... or what are the differences between the beliefs of Protestants and Catholics... I have found that these lessons have been very, very beneficial toward my understanding of people and their belief systems in general. However, I don't know if school-aged kids are mature enough to take those lessons at their proper surface value in order to gain something valuable from them. Not to mention, I don't believe that their parents (most - not all) are open enough to allow those lessons.
What I would opt for instead would be lessons on tolerance - in all areas, not just religion; political, cultural, and gender-based as well. If they learn tolerance, and are able to appreciate, rather than degrade, the differences, that would go a long way toward openess and understanding. I'm not saying that because one is tolerant, one has to accept certain changes - just that, if you learn tolerance, you're more apt not to be ethnocentric and, instead, if changes need to be made, you're better armed with a knowledge base that would afford you the opportunity to make those changes.
