This is according to Quran interpreter Mohammad Ali Ansari. Speaking at an online session about the verses of Surah Qaf, he elaborated on points deduced from the Surah about how the Quran guides people. Here are excerpts from his speech at the session:
Verse 36 of Surah Qaf says: “How many an ancient town who were much stronger than them (unbelievers) did We destroy. (In vain), they wandered through the land in search of a place of refuge from Our torment.”
After several brilliant verses in Surah Qaf about the three major principles of monotheism, prophethood and resurrection, God has a warning in this verse (36), a warning that gives hope to the Holy Prophet (PBUH) on the one hand and frightens disbelievers and deniers on the other. In several other verses of the Quran, too, we read about previous civilizations that were at the peak of their might but were ultimately destroyed.
In the next verse of the Surah (Verse 36), God says: “Surely, in this there is a Reminder for he who has a heart or listens attentively while witnessing.”
The word heart in the Quran has not been mentioned even once to refer to the physiological heart but it is a name referring to the soul and spirit when the issue of understanding is the focus. Because the spirit is the source of understanding, it is referred to as heart. So this verse says if someone has the power of comprehension and reflects on these verses of the Quran, he comes to his senses and flames of thought and guidance are ignited in him.
Then it says: “or listens attentively while witnessing”. Here it means that even one does not have wisdom and understanding, at least he should attentively listen.
So according to what was said, the Quran has the capacity to guide all human beings. But are all people guided? No they aren’t. Because there is a precondition and that is being unbiased and having no obstinacy.
Human beings are two kinds. Some are those who face issues with reflection and thought. They do not speak without thinking first. These people have the capacity to use their intellect to analyze issues. But many humans may not have this capacity. They accept what they hear without thinking if it appeals to them.
We have two types of reason (in Islam): what has been narrated and the intellect. The Holy Quran recognizes both. That is why it says he benefits from the Quran who either reflects on its verses and find its guidance or listens to those who have sensibly and scholarly analyzed them.