What do you mean “will”? They already have and have done since the time of their prophet’s death when he did not name a successor. The Sunni’s versus the Shiite’s. The time of the Ottoman Empire in which the Wahabi’s - who now control the House of Saud - went through the Arabian peninsula and claimed other mooslimes committed shirk. Shirk is worse than apostasy in ISlime.
Sunni’s believe shiites are not muslims and even have decreed it multiple times through fatwas.
Wahabi’s and Salafi’s are the most violent of sects of the Islimic faith. A mere mention by a cleric to one of those faiths can spell death for ANYONE. Tell me they “will” when they already have turned on their own.
Sorry you are offended. When I use the word refer to something that will (oh damn! there’s that word again) with the implication that it is habitual activity. Habitual means something that people have done as a matter of course for a long time. The format of a comment is entirely to small to give the entire history of Islam so that you will not be offended. Either go back and read the whole comment or learn what the various parts of “to be” are and how they are used in English.