One of the worst was my knowledge of the crusades, where I must admit to being as tragically uninformed as the president. I had previously thought the only thing I had in common was Obama was bipedalism.
For starters, get yourself over to Sense of Events to read "Not Every Christian is Perfect"; a link to this. "Not every Christian is perfect. Jesus was. Not every Muslim is a terrorist. Muhammad was."
The crusades were completely defensive, reactionary response to CENTURIES of a Muslim onslaught by jihadists. The purpose of the crusades were to free Christians. The purpose of jihad (Islam’s march) was to conquer and kill the kaffir (non-muslims).
There is absolutely no moral equivalence between the two.