I think a good place to start is by analyzing the religious
atmosphere of the time, and not necessarily the religions themselves. If I get any of this wrong, please correct me:
- Religions were all-prevalent at every level of both society and government
- There were crusades.
- Religions were, for the most part, organized. I think the only significant exception to this were the germanic traditions (Odin, etc).
- Religions of Europe recognized gods.. No exceptions.
- Gods were often recognized as power-beings. That is, they were worshiped because if you didn't, they would strike you with lightning and curse your family for seven generations. (Greek/Germanic)
- One did not merely "change religions". They told you what was and was not proper to do, and anything outside that scope was heretical and blasphemous.
- To that end, what a religion said was "right" and "wrong" was usually law. (Judaism/Greek/Christianity)
- The teachings of the "church" and the teachings of the "prophets" are not necessarily the same. (Christianity, others?)
