> I have always felt that Parasi and Hindu communities are exceptional example of how religious groups with opposite viewpoints can live next to each other and peacefully.

I think the primary reason for this is that neither religion has a concept of converting someone to their religion. Same is true for Judaism, and probably for most ancient religions. As no one was actively trying to convert the other person, wars were fought over territory and resources, and not over who had better gods. It is only when proselytizing became a requirement did we start seeing religious wars.