Inna allatheena yakhshawna rabbahum bilghaybi lahum maghfiratun waajrun kabeer (surah Mulk: 12)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(67:12) Surely forgiveness and a mighty reward *19 await those who fear Allah without seeing Him. *18

Innal lazeena yakhshawna rabbahum bilghaibi lahum maghfiratunw wa ajrun kabeer

*18) This is the real basis of morality in religion. A person's refraining from an evil because it is an evil in his personal opinion, or because the world regards it as an evil, or because its commission is likely to bring loss in the world, or because it may entail a punishment by a worldly power, is a very flimsy basis for morality. A man's personal opinion may be wrong, he may regard a good thing as bad and a bad thing as good because of some philosophy of his own. In the first place, the worldly standards of good and evil have never been the same: they have been changing from time to time. No universal and eternal standard in the moral philosophies is found today, nor has it ever been found before. The fear of worldly loss also does not provide a firm foundation for morality. The person who avoids an evil because he fears the loss that may result from it for himself, cannot keep himself from committing it when there is no fear of incurring such a loss. Likewise, the danger of the punishment by a worldly power also is not something which can trun a person into a gentleman. Everybody knows that no worldly power is knower of both the seen and the unseen. Many crimes can be committed unseen and unobserved. Then, there are many possible devices by which one can escape the punishment of every worldly power; and the Taws made by a worldly power also do not cover all evils. Most evils are such as do not come within the purview of the mundane laws, whereas they are even worse than the evils which they regard as punishable. That is why, the Religion of Truth has raised the edifice of morality on the basis that one should refrain from an evil in fear of the unseen God Who sees man under all conditions, from Whose grasp man cannot escape in any way, Who has given man an all-pervading, universal and everlasting criterion of good and evil. To forsake evil and adopt good only out of fear of Him is the real good which is commendable in religion. Apart from this, if a man refrains from committing evil for .any other reason or adopts acts which in view of their external form are regarded as good acts, his these moral acts will not be worth any merit and value in the Hereafter, for they are like a building which has been built on sand.
*19) That is, there are two inevitable results of fearing God unseen: (1) That whatever errors and sins one will have committed because of human weaknesses, will be forgiven provided these were not committed because of fearlessness of God; and (2) that whatever good acts a man performs on the basis of this belief, he will be rewarded richly for them.