Quotes from David H. Greenlee

The realization that Jews and/or Christians first used all of the technical religious vocabulary of the Qur'an and all of the forms of the Five Pillars of Islam (except references to Muhammad and Mecca) encouraged them to develop a liturgy using biblical content but Muslim forms.

They called themselves "Muslims," "real Muslims," "completed Muslims," "Muslim followers of Isa," Mu'min ("believers," a term used by both Muslims and Christians), and some "Christians," especially when they had become the majority. • The traditional Muslims called them "Muslims if they say so" or "Christians." • Traditional Christians are largely unaware of them.