What is the favor in Allah's saving Muslims from the Fire through Islam? Would they not be considered among the People of the Fatrah had Islam not come?

The Arabs before the prophetic mission were not among the 'Ahl al-Fatra' (people of the interim period), but rather they held remnants of the religion of Abraham, such as the Hajj. There were monotheists among them, like Zayd ibn 'Amr ibn Nufayl and Waraqa ibn Nawfal. However, whoever among them died upon polytheism, such as the Prophet's father and the father of the man who was asked about, their destiny is Hellfire, because the call of Abraham and other prophets had reached them. The polytheist deserves punishment for disobeying the call of the messengers. Allah has bestowed His grace upon the Ansar and others by saving them from the Fire through the sending of the Prophet, peace be upon him, to them, as they were on the brink of a pit of it.