Caliphate: Islamic World's 'Dream Come True'

JERUSALEM, Israel -- When ISIS leader Abu al-Bagdadi established a new caliphate this summer called the Islamic State, it sent shock waves through the Middle East.

The so-called Islamic State became the first caliphate in nearly 100 years. When al-Bagdadi made his announcement, other Islamist groups, like al Qaeda and the Muslim Brotherhood, condemned it.

Regardless of the internal competition, the caliphate would be a dream come true in the Islamic world.

"This dream holds together some kind of feeling that under the caliphate there is going to be a wonderful Islamic world," professor Moshe Sharon, an expert on Islam, told CBN News. "There's going to be unity of all the Muslims. There's going to be a world power that could not be matched by anything."

Sharon said the caliphate began after the death of Mohammed.

"Immediately after the prophet's death, somebody had to lead the community," he continued. "In the Arabic world, caliph is successor, someone who takes the place of."

A long line of these caliphs have ruled during Islam's 1,400-year history.

"This huge empire that was created was called the caliphate, which means this huge territory, this huge Islamic community at the head of which is somebody… who substitutes for the prophet," Sharon explained.

"But it's not true basically," he continued. "It substitutes for God Himself because God is in heaven and somebody has to look after the faithful on earth, and he is a caliph."

On earth, the caliph fights the non-Muslim world, called in Islam "the house of war."

"It's a mistake to think he [the caliph] is like the pope of the Muslims. He is a political and military leader that under him all the Islamic world is united, and of course the war and the fighting against the Christian world would be far easier," Sharon said.

Today the jihadist offensive in the Middle East stretches from the Gaza Strip to Iraq.

"It's all part of an offensive move by forces that have different names -- ISIS, Hamas, Islamic Jihad, al-Aksa Martyrs Brigade, what have you. But they're all on a mission and that is to build a caliphate," Middle East expert Joel Rosenberg told CBN News.

Rosenberg calls it a religious war for these Muslims.

"To kill every Jew and Christian in their way and to kill every Muslim who doesn't believe in their radical way and this is a move," he continued. "And why is it happening now? In part, it's happening because they believe the time for the caliphate has come."

Sharon said Jerusalem is the prize and world domination their goal.

"The major aim of the caliphate is to rule the world, and this can be done under the leadership of one caliph whom he himself only can declare a holy war, a jihad," he said.

More than a decade after 9/11, the West is still coming to grips with Islam's "holy war."