Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, who states: “Allah tells us in the Qur’an, “We are not in the habit of punishing a nation until We have sent a messenger ( to them).” (Al-Isra’: 15) bidding them of what they must be doing and forbidding them of what they must be refraining from. Based on numerous such verses in the Qur’an, great scholars such as Imam Al-Ghazali have stated that those who have not heard of the message of the Prophet Muhammad, peace and blessings be upon him, will not be punished for failing to accept his message. To punish people for failing to accept a message that they know nothing about is utterly contrary to the divine justice which is at once immaculate and beyond question.
While it is true that they will not be punished for their failure to accept the message of Prophet Muhammad, peace and blessings be upon him, however, one must not conclude from this they are totally free of any accountability for their actions. Allah tells us repeatedly in the Qur’an that He has sent a messenger in every nation with the right guidance, and that each messenger spoke the language of the people he was sent to.
Furthermore, we are also told that Allah has created every human being with an innate knowledge of what is good for it and what is bad for it, and that everyone has a responsibility to foster such virtues that his nature recognizes as good and shun those that are abhorrent. (See Surat Ash-Shams: 7-9 )
To conclude: Those who have not heard of the message of the Prophet Muhammad, peace and blessings be upon him, will be judged by Allah by the message they have received from earlier prophets and messengers that were sent to them as well as by the innate sense of good and bad embedded in their
own nature.”

Given the above, it becomes clear that the Prophets who came before Islam and their peoples were not required to believe in the Shari`ah of Islam even if all divine messages before Islam call for monotheism and submission to Allah which are the core and essence of Islam. So, people before Islam were required to follow the guanidine that came to them via their prophets and messengers.

Moreover, Sheikh `Atiyyah Saqr, former head of Al-Azhar Fatwa Committee, states the following: “As for people who survived in a period of time where there was no Prophet sent by Allah, they are known as Ahl al-Fatrah.
People, who died before the advent of Islam will enter Paradise if they had believed in the Divine Messages sent to them. However, those who did not believe in those Messages are disbelievers and they will not enter Paradise.
However, there is disagreement among Muslim scholars regarding those who had no access to the call of any Prophet during their lifetime.
Some Muslim scholars maintain that this group of people should have pondered over Allah’s Creation till they reach the truth. If they managed to reach the truth by their deep thinking, then they will be spared Allah’s Punishment, but not vice versa.
Other Muslim scholars state that people are to adhere to religious ordinances and to proclaim faith only if Allah Almighty sends them a divine legislation through a Messenger or a Prophet. This group backed their view by citing the following verse: “We never punish until We have sent a messenger.” (al-Isra’: 15)
In conclusion, we would like to direct our questioner’s attention to the fact that such a question is not a necessary part of Islamic legislation, and questions of this kind shouldn’t preoccupy the mind of a Muslim. The fate of such people known as “Ahl al-Fatrah” are, by and large, left to Allah Almighty Who will judge them according to their deeds.”