Notably, they didn’t claim responsibility. Contrary to media myth, the Islamic State does not have a record of claiming responsibility for jihad attacks in which it was not involved. But they’re cheering nonetheless: “It’s time to say goodbye to your oratory polytheism.”

The bemused pursuers of “Muslim-Christian dialogue” may find this puzzling, thinking that Muslims recognize Christians as fellow monotheists, and will dismiss it as “extremism.” However, the Qur’an itself, which any Christian involved in “interfaith dialogue” should read and study, but which none will, is quite clear that Christians are polytheists:

Those who believe in the divinity of Christ are unbelievers: “They have certainly disbelieved who say that Allah is Christ, the son of Mary.” — Qur’an 5:17 (cf. 5:72)

Jesus is not the Son of God and belief in the Trinity is “excess”: “O People of the Book! Do not exaggerate in your religion nor utter anything concerning Allah save the truth. The Messiah, Jesus son of Mary, was only a messenger of Allah, and his word which he conveyed to Mary, and a spirit from him. So believe in Allah and His messengers, and do not say ‘Three.’ Cease! It is better for you! Allah is only One Allah. It is far removed from his transcendent majesty that he should have a son. His is all that is in the heavens and all that is in the earth. And Allah is sufficient as Defender.” — Qur’an 4:171

And: “It is not befitting to Allah that he should beget a son. Glory be to him! When He determines a matter, he only says to it, ‘Be,’ and it is.” — Qur’an 19:35

“Notre Dame FIRE: ISIS fanatics praise blaze and call it ‘RETRIBUTION,'” by Rebecca Perring, Express, April 16, 2019: