Of course, islam 101 (the way of mohamed) tells him so.
Polish convert to Islam: “We will hold mass executions in St. Peter’s Square”
The Islamic State has previously vowed: “We will conquer your Rome, break your crosses, and enslave your women, by the permission of Allah.”
“Polish male convert for ISIS: You will die like all infidels,” RMF FM 24 (translated by Weronika Kania), August 5, 2015:
National radio RMF FM has recently publicized parts of interview with the Polish jihadi named Adrian Al N., in which he describes his journey to Syria and escaping the Polish service services before reaching his destination and adopting the new name Abu Bakr Al Sham. In the latest interview with the weekly ABC magazine, the convert confesses: “I will fight and become a martyr if necessary.” He also makes predictions of a “cruel judgement” and the transition of the war into European territory.
He also makes an appeal to the readers: “Convert while you still have the time and before we come to your homes to check your faithfulness to the Only God. If you fail to do so, you shall die like all infidels. Such is the law of Allah. We shall win and come over to Rome. We will hold mass executions in St. Peter’s Square.”
The interview carried out with the Polish jihadi is the first clear testimony of the participation of Polish nationals in the Islamic jihad led by ISIS. The man is one of up to 10 Polish converts who are now directly cooperating with the Islamic State or fighting within its ranks. Polish security services are aware of their existence.