What changed in the Holy Land between 550 CE and 750 CE? How might this have affected relationships between Jewish people, Roman Catholic Christians, Eastern Orthodox Christians, and Muslims?

Between those years, the Holy Land went from being part of the Byzantine Empire, to being part of the Muslim Empires or Caliphates that formed since the death of Muhammad.

Explanation:

This affected relationships between people from the religions listed in the question, because while before, christians were the ruling group in the land, muslims became the rulers after their conquests.

The christians, both catholic and orthodox, saw Muslim control over the Holy Land as outrageous, because of precisely the fact that this land is considered Holy for Christians, because it is the place where Jesus was born and lived.

For this reason, from the 11th century onwards, the Pope launched a series of wars with the goal or retaking the Holy Land from Muslim control. These wars are known as the Crusades.