Do they not reflect on themselves?

The promise of Allah. Allah does not fail in His promise, but most of the people do not know. They only know the outside appearance of the life of the world, and they are heedless of the Hereafter. Do they not reflect on themselves? Allah created the heavens and the earth and whatever lies between them in Truth and for an appointed term. Yet many people deny that they will meet their Lord! Have they not travelled throughout the land to see what was the end of those before them? They were greater than them in power, and they plowed the earth and built it up more than they have built it up. Their messengers came to them with clear proofs. Allah would have never wronged them, but it was they who wronged themselves. Then most evil was the end of the evildoers for denying and mocking the signs of Allah. Allah begins creation; then He will repeat it; then to Him you will be returned.

— Quran 30:6–11

here a commentary by Towards Understanding the Quran:

(30:8) Do they not reflect on themselves? 5 Allah created the heavens and the earth and whatever lies between them in Truth and for an appointed term. 6 Yet many people deny that they will meet their Lord. 7

5. This in itself is a strong argument for the Hereafter. It means this: “If these people had reflected over their own selves, apart from the external phenomena, they would have found in themselves the arguments which prove the necessity of a second life after the present life. There are three special characteristics of man which distinguish him from the other creations on the earth:”

(1) The earth and the countless things around it have been subjected for him, and he has been granted vast powers to exploit them.

(2) He has been life free to choose a way of life for himself. He can follow the way of belief or disbelief, obedience or sin, virtue or vice, as he likes. Any way of life, right or wrong, that he chooses, he is helped to follow it and allowed to use and exploit all the means and resources provided by God, whether the way chosen is of God’s obedience or of His disobedience.

(3) An innate moral sense has been placed in him, by which he discriminates between the voluntary and the involuntary actions; he judges the voluntary acts as good and bad, and decides spontaneously that a good act ought to he rewarded and an evil act ought to be punished.

These three characteristics which are found in man’s own self serve as a pointer to the fact that there must be a time when man should he called to account for his deeds, when he should be asked how he used the powers delegated to him over what he had been given in the world, when it should be seen whether he had adopted the right way or the wrong way by use of the freedom of choice given to him, when his voluntary acts should be judged, and good acts be rewarded and evil acts punished. This time inevitably can come only after man’s life-activity has ceased and the account book of his actions closed, and not before it. And this time should necessarily come only when the account book of not one man or of one nation but of all mankind has closed. For on the passing away of one man or of one nation, the influence that he or it has generated by his or its acts does not cease to operate. The good or bad influence left by him should also be credited to his account. How can accountability be carried out and full rewards and punishments given with justice unless the influences are allowed to run their full course. Thus, man’s own self testifies that the position he occupies in the world by itself demands that after his present life there should be another life when a court should be established, his life-record examined justly and every person rewarded or punished according to his deeds.

6. In this sentence, two more arguments have been given for the Hereafter. It says that if man makes a deep observation of the system of the universe, he will see two things very outstanding about it: First, that the universe has been created with the truth. It is not a plaything of a child, which he might have made to amuse himself, and whose making and un-making might be meaningless. But it is a serious system whose every particle testifies that it has been created with great wisdom, its each component has a law underlying it, and everything in it has a purpose behind it. Man’s whole social and economic life and all his sciences and arts are a witness that whatever man has done in the world became possible only because he was able to discover the laws working behind everything and the purpose for which it was made. Had he been placed as a puppet in a lawless and purposeless toy-house, no science and no civilization and social life could be conceived. Now, how does it stand to reason that the Wise Being Who has created this world with such wisdom and design and Who has placed in it a creation like man, who is endowed with great mental and physical capabilities, powers and authority, freedom of action and choice, moral sense and entrusted with unlimited means and resources of the world, would have created him without a purpose and design? That man would live a full life involving both goodness and evil, justice and injustice, virtue and vice, and end up in the dust, and his good and evil acts will not bear any fruit? That each act of man will influence his own life as well as the lives of thousands of other men like himself and countless other things in the world, for good or for evil, and the whole record of his life-activity will be just set aside after his death, without accountability?

The other thing that becomes apparent after a deep observation of the system of the universe is that nothing here is immortal. Everything has an age appointed for it after attaining which, it dies and expires, and the same is the case with the universe as a whole. All the forces that are working here are limited. They can work only till an appointed term and they have inevitably to run out in time, and this system has to end. In the ancient days the philosophers and scientists who said that the world was eternal and everlasting could have their way, due mainly to lack of knowledge. But modern science almost definitely has cast its vote in favor of the God worshipers in the debate that had been going on since centuries between them and the atheists regarding the eternal and the temporal nature of the world. Now the atheists are left with no leg to stand on. They cannot claim on the basis of reason and knowledge that the world has existed since eternity and will exist forever and there is going to be no resurrection. The ancient materialistic creed rested on the belief that matter was indestructible, only its form could be changed, but after every change matter remained matter and no increase or decrease occurred in its quantity. Therefore, it was inferred that this material world had neither a beginning nor an end. But now the discovery of the atomic energy has demolished the entire materialistic edifice. Now it has come to light that energy changes into matter, and matter changes back into energy with the result that nothing persists, neither form nor appearance. The second law of Thermodynamics has proved that this material world has neither existed since eternity nor will last till eternity. It certainly began in time and has to end in time. Therefore, it is no longer possible to deny the Hereafter even according to science. And obviously, when science has surrendered, how will philosophy stand to deny the Hereafter?

7. “Disbelievers in the meeting with their Lord”: disbelieve that they have to appear before their Lord after death.

source: Surah Ar-Rum 30:1–10 — Towards Understanding the Quran — Quran Translation Commentary — Tafheem ul Quran