Allah T'ala says in the Holy Quran:
إَنَّ الَّذِينَ لاَ يَرْجُونَ لِقَاءنَا وَرَضُواْ بِالْحَياةِ الدُّنْيَا وَاطْمَأَنُّواْ بِهَا وَالَّذِينَ هُمْ عَنْ آيَاتِنَا غَافِلُونَ
أُوْلَـئِكَ مَأْوَاهُمُ النُّارُ بِمَا كَانُواْ يَكْسِبُونَ
Surely those who do not expect to meet Us, who are gratified with the life of the world and content with it, and are heedless of Our signs,their abode shall be the Fire in return for their misdeeds. (The Holy Quran, 10:7-8)
The statement that is being made here is that rejection of the doctrine of the Hereafter necessarily entails the punishment of Hell, and the argument that is being proffered in support of it is that those who are oblivious to the Hereafter commit, because of their disbelief in it, evil deeds which can only lead to them suffering the torments of Hell. This argument is corroborated by the entire record of man's past. It is quite clear that the lives of those who do not believe that they will not be held to account by God for their deeds; who work on the assumption that life is merely confined to the span of worldly existence; who measure human success or failure only in terms of the extent of material comfort, fame and power that a person is able to enjoy; who under the influence of such materialistic notions do not even care to pay attention to those signs of God which point to reality, assume an altogether wrong direction with the result that their life is vitiated. Hence they live a totally unbridled life, develop the worst possible character traits, and fill God's earth with injustice and corruption, with sin and transgression, and ultimately end up meriting the punishment of Hell.
The above argument about the Hereafter is drawn from human experience itself. Although in the present verse the argument is found only in an implicit form, it is spelt out at several other places in the Qur'an. The argument essentially is that unless man's character rests on the consciousness and conviction that he will have to render an account for all his deeds to God, both man's individual and collective behaviour will fail to have sound basis and direction. It would seem, therefore, to be worth asking: why is this so? Why is it that once this consciousness and conviction are altogether ended or greatly enfeebled, the human character turns to iniquity and corruption? Had affirmation of the Hereafter not been in conformity with reality, and conversely, had its denial not been opposed to it, then the evil consequences flowing from the denial of the Hereafter would not have been found with such unfailing regularity. If adherence to a proposition invariably leads to good results, and failure to adhere to it invariably leads to evil consequences, then this definitely proves the proposition to be true.
In an attempt to refute the above argument it is sometimes contended that even atheists who reject the Hereafter and follow a materialistic approach to life often lead lives that are on the whole good and decent, that they hold themselves free from corruption and injustice. Not only that but also that their actual conduct is characterized by righteousness and benevolence. However, only a little reflection will make apparent the fallacy underlying this argument. For if one were to examine any atheistic or materialistic philosophy or ideology one will not find in them any basis for righteous behaviour which draws such lavish praise from so-called 'righteous' atheists. Nor can it be established by logical reasoning that an atheistic philosophy of life provides any incentive to embrace such virtues as truthfulness, trustworthiness, honesty, faithfulness to one's commitment, benevolence, generosity, preferring the interests of others to one's own, self-restraint, chastity, recognition of the rights of others, and fulfilment of one's obligations. The fact is that once God and the Hereafter are relegated to oblivion, the only practicable course left for man is to anchor his morality on utilitarianism. All other philosophical ideas which are expounded are merely theoretical embellishments and have no relevance for man's practical life.
As for utilitarian morality - no matter how hard we might try to broaden its scope - it does not go beyond teaching man that he ought to do that which will yield to him or to his society some worldly benefit. Now since utility is the criterion of all acts, such a philosophy tends to make man cynical, with the result that in order to derive benefits, he will not differentiate between truth and lie; between trustworthiness and treachery; between honesty and dishonesty; between loyalty and perfidy; between observing justice and committing wrong. In short, a person under the spell of utilitarian ideas will be ready to do a thing or its opposite, depending on what serves his interests best. The conduct of the British is illustrative of this stance. It is sometimes contended that though the British have a materialistic outlook on life and generally do not believe in the Hereafter, they are more truthful, fairer, and more straightforward and faithful to their commitment.
The fact, however, is that the tenuous character of moral values under a utilitarian moral philosophy is amply illustrated by the character of the British.
For their actual conduct clearly shows that they do not consider moral values to have any intrinsic worth. This is evident from the fact that even those values which are held by the British to be good in their individual lives are brazenly flouted when they act as a nation. Had the qualities of truthfulness, justice, honesty and faithfulness to one's committed word been regarded as intrinsic virtues, it would have been altogether out of the question for the elected rulers of Britain to cynically violate all moral principles in governmental and international affairs and yet continue to retain the confidence of the British people. Does such a behaviour of a people who do not take the Hereafter seriously prove that they do not believe in absolute moral values? Does it also not prove that, guided by concern for material interests, such people are capable of following mutually opposed views simultaneously? (The same arguemnt can be made against the United States and many other governments and societies of today.)
Nevertheless, if we do find some people who, in spite of their not believing in God and the Hereafter, consistently adhere to some moral virtues and abstain from evil, there should be no mistaking that their righteous conduct and piety represents the continuing influence which religious ideas and practices have over them - even if unconsciously - rather than their subscription to a materialistic philosophy of life. If they possess any portion of the wealth of morality, there can be no doubt that it was stolen from the treasure-house of religion. It is ironical that such persons are now using the same wealth derived from religious sources, to promote an irreligious way of life. We consider this an act of theft because irreligiousness and materialism are altogether bereft of morality. (slightly edited version of text taken from Tafheemul Quran)