The founding of the Abrahamic traditions took place in the land of Israel. All the three monotheistic religions think of that land as sacred. It fell into Islamic hands, the Christians fought the Crusades, and the Muslims fought tooth and nail to hold onto those holy places. In 1948 the United Nations said the Jews should be put into that country and the indigenous Muslims have to move.
Shoot, people even get mad when their house is foreclosed on. Often they take out all the light fixtures, smash in the walls, take the appliances and kitchen cabinets, not to mention taking out all the toilets and the garage door. That's what people do when the don't have any religious belief that the land they occupy is sacred.
Is the Israeli-Palestinian conflict hard to understand? Not to me.