Complex sentence: Al-Yaqoubi believes that ISIS constitutes the most serious threat Islam has ever faced and that Muslim scholars are obliged to respond with a counter-narrative that elucidates the reality of Islam and its commitment to tolerance.
Split into simpler sentences: Al-Yaqoubi is of the view that ISIS constitutes the most serious threat Islam has ever faced. Therefore, the Muslim scholars are obliged to respond with a counter-narrative that elucidates the reality of Islam and its commitment to tolerance.