The Middle East is in constant battle, and war. Being the most diverse in different religions, many of these religions don't like eachother starting hundreds of years ago. You have Jews against Arabs (Muslims), Sunni's against Shi'ites. The problem between the Sunni's and Shi'ites was that the Sunni's wanted Abu Bakr as their religious leader whereas the Shi'ites wanted Ali as their leader. Abu Bakr won, and this caused a great upset which lead to him dying and then Ali taking power and then getting killed and his son taking his place. This has caused a turmoil and there is a very permanent division between the two. As for Jews and Arabs, their conflict started years ago with Ishmael and Issac. After WWll gas fueled their dispute when the UN gave the land of Israel to the Jews, which then the Arabs protested and didn't want. They wanted the Jews gone, however the Jews have the right of that land because it was promised to them. So ever since then, constant battle occurs because where the Jews thought they were allowed they are basically hated.

    When talking about Jerusalem in accordance to Christians, Muslims and Jews, the easiest way to explain this is that Jerusalem is seen as a holy place for all of these religions. They all see it as a holy city for them. Jerusalem is the holiest city to the Jews. For Christians they see Jerusalem as a place where Jesus was present and find that near and dear to their heart. Muslims believe any prophets they have known were associated themselves with that city.