ISIS have struck at the heart of Christianity, by publishing a front page image in their official magazine of a black Islamic State flag flying above the Vatican.
The magazine, called Dabiq, is more a propaganda rag than a serious publication, and its fourth edition calls for all out war against the Catholic Church as well as on Christians everywhere.
It's not hard to see what the article in the ISIS magazine is all about, as it is entitled "The Failed Crusade," and talks of conquering Rome and breaking the crosses of Christians.
An excerpt from the hate-filled article reads, "Every Muslim should get out of his house, find a crusader and kill him," urging Muslims to "kill every Crusader possible."
The magazine's name, Dabiq, is derived from a town in northern Syria where, in 1516, the Ottomans defeated the Mamluks, establishing the last Islamic caliphate.
According to that publication, it is normal under Islamic law for women of infidels to be captured, used for sex, and then sold as slaves in the market to the highest bidder.
And just last month, officials at the Vatican told reporters they had beefed up security following the threats from ISIS, which they are taking very seriously. Among the various new steps put in place, for fear of an imminent threat, is to restrict air space above Vatican City itself.
According to notorious jihadi recruiter Bosnian Imam Bilal Bosnic in Italy, extremist militants will bring Islam even to the heart of Christendom, even if he does not live to see it.
He said in a recent speech, "In time the whole world will be an Islamic state. Our goal is to make sure that even the Vatican will be Muslim."
The ISIS threat isn't just limited to Christians, Catholicsl or the Pope though, as the group have said in the past that Jews, other infidels, and even moderate Muslims should be killed under certain circumstances, if they stand against the Islamic State's principles.