The Quran

وَاختِلافِ اللَّيلِ وَالنَّهارِ وَما أَنزَلَ اللَّهُ مِنَ السَّماءِ مِن رِزقٍ فَأَحيا بِهِ الأَرضَ بَعدَ مَوتِها وَتَصريفِ الرِّياحِ آياتٌ لِقَومٍ يَعقِلونَ

Ali Unal

And in the alternation of night and day (with their periods shortening and lengthening), and in the provision (rain) God sends down from the sky and reviving thereby the earth after its death, and in His turning about of the winds — (in all this) there are (clear) signs for a people who are able to reason and understand.¹

Verse 3 states that what is manifest to the eye through the universe is enough to enable faith, for believers see the heavens and the earth replete with manifest signs of God’s Existence, Oneness, and Lordship. However, verse 4 calls us to study the parts of creation or the universe. When we study our existence and the existence and life of animals on the earth, our faith is strengthened and develops into certainty. Bediüzzaman Said Nursi reminds us that to strengthen our faith, we should reflect generally on the outer world (the heavens and the earth), but be more detailed and penetrating when we study our own creation and structure.
The third verse uses the word believers; this is different from the usage of the phrase, those who believe. This form denotes those who have attained faith and in whose hearts faith has been established. The phrase, those who believe, refers to those who have acknowledged faith. When the Qur’ān uses the verb believe in the simple present tense, which in Arabic denotes actions expressed in English by both the present continuous and simple present tenses, it signifies that one is journeying in faith. This journeying continues until it has been established in the heart. In time, this faith continues to be strengthened and becomes certainty (yaqīn). Certainty also has degrees: these are certainty arising from knowledge, certainty coming from observation, and certainty arising from direct experience. According to many, certainty of the truths of faith arising from direct experience can be attained in the Hereafter. Since journeying or developing in certainty continues throughout life, the Qur’ān usually uses it in the verbal form and in the (Arabic) simple present tense. The fourth verse here also uses the verbal form in this tense. So, the more we study ourselves and other creatures on the earth, the more we become certain of the truths of faith.
As for verse 5, it calls people to approach some important phenomena in the life of the universe with their reason or intellect, and it urges them to reflect on them, reason them out, and try to understand them, with their full meaning and functions in the complex web of creation and life. Such an approach to, and study of, these phenomena leads people who can use their reason in the proper way to be able to distinguish between truth and falsehood, and between what is good and to their benefit and what is evil and to their harm. This is a more advanced rank that one can attain through certainty of faith. Without faith and certainty, reason alone cannot raise one to the rank where this distinction can be made. The person who has risen to the rank where reason or intellect, enlightened by faith and certainty, can be used in the proper way can easily perceive that whatever the Qur’ān says is absolutely true; and they do not see any conflict between the Revelation or the reported knowledge (the Qur’ān and the Sunnah) and reason, or between the Religion and science (not scientism). If there should sometimes seem to be a conflict, this kind of reason or intellect can correctly reconcile it. Said Nursi refers to this fact when he says, “If reported knowledge and reason conflict, reason is preferred, provided the reason is the kind of reason (fully enlightened by the Revelation)” (Muhakemat, 13).
By referring to the believers (believing individuals), the third verse implies that an individual can have a general view of the universe that enables him or her to attain faith. By contrast, the fourth and fifth verses mention people who seek certainty and people who use their reason, respectively, thus suggesting that a detailed study of existence and existential phenomena is important in reaching certainty and using reason properly.
We should point out here that acknowledgment and profession are essential to faith, unless there is an absolute, religiously accepted obstacle. Although certainty is a deeper degree in faith, it cannot be faith (īmān) unless acknowledgment and profession accompany it. For there have been many people whose consciences have been convinced of the truths of faith, yet they have knowingly and obstinately refused to believe. The verse, They rejected them out of mere iniquity and self-exaltation, although their consciences were convinced of their being true (27: 14), refers to this.