The question whether there is a life after death does not fall under the jurisdiction of science as science is concerned primarily with the classification
and analysis of sense data. Moreover, man has been busy with scientific enquiries and research, in the modern sense of the term, only for the last few centuries, while he has been familiar with the consept of
life after death since times immemorial.
All the prophets of God called their people to worship God and to believe in life after death. They laid so much emphasis on the belief in life after death that even a slight doubt in it meant denying God and made all the beliefs meaningless.
The very fact that all the prophets of God have dealt with this metaphysical question of life after death so confidently and so uniformly - the gap between their ages being thousands of years - goes to prove that the source of their knowledge of life after death as proclaimed by them all, was the same, that is, Divine revelation.
We also know that these prophets of God were greatly opposed by their people, mainly on the issue of life after death as their people thought it impossible. But inspite of opposition the prophets won so many sincere followers.
The question arises what made those followers forsake the established beliefs, traditions and customs of their forefathers notwithstanding the risk of being totally alienated from their own community? The simple answer is that they made use of their faculties of mind and heart and realized the truth.
Did they realize the truth through perceptual consciousness? Not so, as perceptual experience of life after death is impossible. Actually, God has given man besides perceptual consciousness, rational, aesthetic and moral consciousness too. It is this consciousness that guides man regarding realities that cannot be verified through sensory data.
That is why all the prophets of God while calling people to believe in God and life after death, appeal to the aesthetic, moral and rational consciousness of man. For example, when the idolators of Makkah denied even the possibility of life after death, the Qur'an exposed the weakness of their stand by advancing very logical and rational arguments in support of it.
Holy Qur'an says, "And he has coined for us a similitude, and has forgotten the fact of his creation, saying: who will revive these bones when they have rotten away? Say: He will revive them who produced them at the first, for He is the knower of every creation. Who has appointed for yoy fire from the green tree, and behold! you kindle from it. Is not He who created the Heavens and the Earth,
able to create the like of them? Yes, and He is indeed Supreme Creator, the All-knowing". [Surah 36 : 78-81]
At another occassion the Qur'an very clearly says that the disbelievers have no sound basis for their denial of life after death. It is based on pure conjectures: "They say, 'There is nothing but our present life; we die, and we live, and nothing but Time destroy's us.' Of that they have no knowledge; they merely conjecture. And when our revelations are recited to them, their only argument is that they say, 'Bring us our fathers, if you speak truly.'" [Surah 45 : 24-25].
Surely, God will raise all dead. But God has His own plan of things. A day will come when the whole universe will be destroyed and then again the dead will be resurrected to stand before God. That day will be the beginning of the life that will never end, and that Day every person will be rewarded by God according to his or her good or evil deed.
The explanation that the Qur'an gives about the necessity of the life after death is what moral consciousness of man demands. Actually if there is no life after death, the very belief in God becomes irrelevant or even if one believes in God, that would be an unjust and indifferent God: having once created man, He is not concerned with his fate.
Surely, God is just. He will punish the tyrants whose crimes are beyond count: having killed hundreds of innocent persons, created great corruptions in the society, enslaved numerous persons to serve their whims etc. Man having a very short span of life in this world, and this physical world too being not eternal, punishments or rewards equal to the evil or noble deeds of persons are not possible here. The Qur'an very emphatically states that the Day of Judgement must come and God will decide about the fate of each soul according to his or her record of
deeds: "Those who disbelieve say: 'The Hour will never come unto us.' Say: 'Nay, by my Lord, but it is coming unto you surely. (He is) the Knower of the Unseen. Not an atom's weight, or less than that or greater, escapes Him in the heavens or in the earth, but it is in a clear Record. That He may reward those who believe and do good works. For them is pardon and a rich provision. But those who strive against our revelations, challenging (Us), theirs will be a painful doom of wrath.'" [Surah 34 : 3-5].