The Prophet Muhammad (saas) made his people—who knew about Allah’s existence but did not think about His superior might and thus failed to appreciate His grandeur—admit Allah’s existence and grandeur. Then, he summoned them to take warning and to have fear in Him:

Say: “To whom does the Earth belong, and everything and everyone in it? Tell me if you know the truth.” They will reply: “To Allah.” Say: “So will you not pay heed?" Say: “Who is the Lord of the Seven Heavens and the Lord of the Mighty Throne?” They will reply: “Allah.” Say: "So will you not fear Allah?” Say: “In Whose hands is the dominion over everything, He Who gives protection and from Whom no protection can be given? Tell me, if you know the truth.” They will reply: “Allah’s.” Say: “So how have you been so bewitched?” (Surat al-Muminun, 84-89)