Scores of churches have been destroyed by the extreme Islamic murderers while millions of Christians have been forced from their hometowns.
Those who don't flee as refugees are instead tortured and killed.
Juliana Taimoorazy, executive director and founder of the Iraqi Christian Relief Council, said: "We gave a lot to Christianity as Eastern Christians, and we gave a lot to humanity as the Assyrian people.
"Our history is 6,700 years old, and we established the first library in the world, among other contributions."
The horrific abuse puts at risk one of the oldest Christian communities in the world in Syria.
The apostle Paul was said to have converted on the road to Damascus, while some Christians in the town of Maaloula still speak Aramaic - the language of Jesus.
In the mountains west of Homs is the castle of Krak des Chevaliers, a fortress for the Knights Hospitaller during the Crusades.
But the castle has now been badly damaged after it was bombed by government jets while it was being used as a base by rebels in Syria's
Meanwhile, in Ninevah Plains in Iraq alone, more than 100,000 Christians have been forced to pack up and leave for good since ISIS occupied the region. In total, more than a million Christians have fled the country since the fall of Saddam Hussein.
Jean-Clement Jeanbart, the Greek Melkite Catholic Archbishop of Aleppo, exclusively told Express.co.uk he would be willing to die at the hands of ISIS to defend Christians in the Syrian city.
He revealed at least 1,000 Christians had been abducted and murdered in Aleppo.
Before the war, it had a Christian population of around 160,000, one of the biggest in the Middle East, but now only 100,000 remain.
He said: "Many people have been abducted, many people have been killed, many people have been beheaded, many people have been persecuted, it is a terrible situation.
"They do not accept anyone different. Anyone who is not like them and with the same choices has not got a right to live."
Only last month, 21 Christians were murdered out of almost 300 who remained in the city of al-Qaryatain after ISIS captured it last August.
Some of the victims - who included three women - died whilst trying to escape while others were killed for breaking the terms of their "dhimmi contracts", which require them to submit to the rule of Islam.
But despite the atrocities, congregations are clinging to their faiths.
Bishop Yousif Habash of Syrian Catholic Eparchy of Our Lady of Deliverance based in New Jersey says even though ISIS may take away everything from the Christians, they cannot take away their faith.
Religious groups and leaders are now calling on their followers to pray for the survival of those being persecuted in Iraq and Syria.
Last month the US accused ISIS of committing genocide against ethnic and religious minority groups in Iraq and Syria. US Secretary of State John Kerry said that the state department had determined Isis to be "responsible for genocide against groups in areas under its control including Yazidis, Christians and Shia Muslims".He added that in 2014 the terrorist group trapped members of the Yazidi religious minority who lived in ISIS controlled areas, killing or enslaving thousands, "selling them at auction, raping them at will and destroying the communities in which they had lived for countless generations".The group also executed Christians "solely for their faith" and forced women and girls into slavery, he said.
It was only the second time that a US administration has designated a mass killing a genocide.