Accordingly, the Prophet ﷺ instructed his Companions to begin with the very thing he had begun with—calling people to pure monotheism. There is, beyond doubt, an enormous difference between those pagan Arabs—who understood perfectly what was being said to them in their own tongue—and the majority of today’s Arab Muslims. The latter do not need to be invited to utter the words lā ilāha illā Allāh, for they already profess them, whatever their various schools, paths, and creeds may be; what they truly need is to grasp more fully the meaning of this noble declaration.
This is a profoundly essential distinction. The first Arabs, whenever the Messenger of Allah ﷺ asked them to say lā ilāha illā Allāh, grew arrogant, as the explicit wording of the Mighty Quran makes clear (1). Why did they react with such pride? Because they understood that the statement requires one to set up no rivals with Allah and to worship none but Him, while they were in fact worshipping others. They called upon beings other than Allah, sought rescue from others besides Him—let alone making vows to others, seeking mediation through others, sacrificing animals to others, and referring their disputes for judgment to others, and so forth.