Answer:
Jerusalem is a sacred city for this three Monotheistic religions. This is due to fact that all of these religions have certain symbols that are connecting them with Jerusalem.
Solomon's temple and Wailing Wall were built in Jerusalem. Temple was built to honor Jewish faith and Wall has significance for both Jews and Muslims. Muhammed ascended to the Heaven from Jerusalem. Tomb of Jesus Christ is in Jerusalem. That is the importance for Christians.
Explanation:
This is probably the most religious center in the world. All religion are having their relics and consider the city sacred. In addition to that we can mention that even religious wars were led for the city and as Christians were saying deliberation of Jesus Christ's tomb.
