Document 1 states that Christians and Muslims both committed appalling atrocities in the name of religion.
This is relevant because then in Europe crusaders would sometimes turn their fury towards Jews sometimes massacring entire cities.
Document 3 states that some people didn’t join the Crusades for religious reasons some of them joined for adventure, estates, and even commercial opportunities.
This is interesting because it is showing that some people would kill just for adventure and estates and that shows why it was so negative. It was so negative because many of those people that were killed probably would have been alive if some of those people that killed for non-religious
reasons didn’t go.
For those reasons the Crusades show to be more negative than positive.